diff --git a/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinJsCompilerType.kt b/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinJsCompilerType.kt
index 05079d9110c..d82ca8f19d8 100644
--- a/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinJsCompilerType.kt
+++ b/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinJsCompilerType.kt
@@ -27,7 +27,7 @@ enum class KotlinJsCompilerType {
 }
 
 val KotlinJsCompilerType.lowerName
-    get() = name.toLowerCase()
+    get() = name.toLowerCase(Locale.ENGLISH)
 
 fun String.removeJsCompilerSuffix(compilerType: KotlinJsCompilerType): String {
     val truncatedString = removeSuffix(compilerType.lowerName)
diff --git a/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/NativeBinaryTypes.kt b/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/NativeBinaryTypes.kt
index 8f56275650c..531950e761c 100644
--- a/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/NativeBinaryTypes.kt
+++ b/libraries/tools/kotlin-gradle-plugin-api/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/NativeBinaryTypes.kt
@@ -10,6 +10,7 @@ import org.gradle.api.Named
 import org.jetbrains.kotlin.konan.target.CompilerOutputKind
 import org.jetbrains.kotlin.konan.target.Family.*
 import org.jetbrains.kotlin.konan.target.KonanTarget
+import java.util.*
 
 enum class NativeBuildType(
     val optimized: Boolean,
@@ -18,7 +19,7 @@ enum class NativeBuildType(
     RELEASE(true, false),
     DEBUG(false, true);
 
-    override fun getName(): String = name.toLowerCase()
+    override fun getName(): String = name.toLowerCase(Locale.ENGLISH)
 
     @Suppress("UNUSED_PARAMETER")
     @Deprecated(
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/compilerRunner/reportUtils.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/compilerRunner/reportUtils.kt
index 8103b5d09b3..2e3ec97ddd7 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/compilerRunner/reportUtils.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/compilerRunner/reportUtils.kt
@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.daemon.client.launchProcessWithFallback
 import org.jetbrains.kotlin.gradle.logging.GradleErrorMessageCollector
 import org.jetbrains.kotlin.gradle.logging.GradleKotlinLogger
 import org.jetbrains.kotlin.gradle.tasks.KotlinCompilerExecutionStrategy
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import org.jetbrains.org.objectweb.asm.ClassReader
 import org.jetbrains.org.objectweb.asm.ClassVisitor
 import org.jetbrains.org.objectweb.asm.FieldVisitor
@@ -59,7 +60,7 @@ internal fun loadCompilerVersion(compilerClasspath: Iterable<File>): String {
     try {
         val versionClassFileName = KotlinCompilerVersion::class.java.name.replace('.', '/') + ".class"
         for (cpFile in compilerClasspath) {
-            if (cpFile.isFile && cpFile.extension.toLowerCase() == "jar") {
+            if (cpFile.isFile && cpFile.extension.toLowerCaseAsciiOnly() == "jar") {
                 ZipFile(cpFile).use { jar ->
                     val versionFileEntry = jar.getEntry(KotlinCompilerVersion.VERSION_FILE_PATH)
                     if (versionFileEntry != null) {
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/AbstractKotlinNativeBinaryContainer.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/AbstractKotlinNativeBinaryContainer.kt
index 109645dcdde..d19ecbadc13 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/AbstractKotlinNativeBinaryContainer.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/dsl/AbstractKotlinNativeBinaryContainer.kt
@@ -4,6 +4,7 @@ import org.gradle.api.Action
 import org.gradle.api.DomainObjectSet
 import org.gradle.api.Project
 import org.jetbrains.kotlin.gradle.plugin.mpp.*
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toUpperCaseAsciiOnly
 
 // DO NOT EDIT MANUALLY! Generated by org.jetbrains.kotlin.generators.gradle.dsl.MppNativeBinaryDSLCodegenKt
 
@@ -42,7 +43,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns an executable with the given [namePrefix] and the given build type. Throws an exception if there is no such binary.*/
     fun getExecutable(namePrefix: String, buildType: String): Executable =
-        getExecutable(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        getExecutable(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns an executable with the empty name prefix and the given build type. Throws an exception if there is no such binary.*/
     fun getExecutable(buildType: NativeBuildType): Executable = getExecutable("", buildType)
@@ -55,7 +56,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns an executable with the given [namePrefix] and the given build type. Returns null if there is no such binary. */
     fun findExecutable(namePrefix: String, buildType: String): Executable? =
-        findExecutable(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        findExecutable(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns an executable with the empty name prefix and the given build type. Returns null if there is no such binary. */
     fun findExecutable(buildType: NativeBuildType): Executable? = findExecutable("", buildType)
@@ -68,7 +69,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns a static library with the given [namePrefix] and the given build type. Throws an exception if there is no such binary.*/
     fun getStaticLib(namePrefix: String, buildType: String): StaticLibrary =
-        getStaticLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        getStaticLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns a static library with the empty name prefix and the given build type. Throws an exception if there is no such binary.*/
     fun getStaticLib(buildType: NativeBuildType): StaticLibrary = getStaticLib("", buildType)
@@ -81,7 +82,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns a static library with the given [namePrefix] and the given build type. Returns null if there is no such binary. */
     fun findStaticLib(namePrefix: String, buildType: String): StaticLibrary? =
-        findStaticLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        findStaticLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns a static library with the empty name prefix and the given build type. Returns null if there is no such binary. */
     fun findStaticLib(buildType: NativeBuildType): StaticLibrary? = findStaticLib("", buildType)
@@ -94,7 +95,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns a shared library with the given [namePrefix] and the given build type. Throws an exception if there is no such binary.*/
     fun getSharedLib(namePrefix: String, buildType: String): SharedLibrary =
-        getSharedLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        getSharedLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns a shared library with the empty name prefix and the given build type. Throws an exception if there is no such binary.*/
     fun getSharedLib(buildType: NativeBuildType): SharedLibrary = getSharedLib("", buildType)
@@ -107,7 +108,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns a shared library with the given [namePrefix] and the given build type. Returns null if there is no such binary. */
     fun findSharedLib(namePrefix: String, buildType: String): SharedLibrary? =
-        findSharedLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        findSharedLib(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns a shared library with the empty name prefix and the given build type. Returns null if there is no such binary. */
     fun findSharedLib(buildType: NativeBuildType): SharedLibrary? = findSharedLib("", buildType)
@@ -120,7 +121,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns an Objective-C framework with the given [namePrefix] and the given build type. Throws an exception if there is no such binary.*/
     fun getFramework(namePrefix: String, buildType: String): Framework =
-        getFramework(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        getFramework(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns an Objective-C framework with the empty name prefix and the given build type. Throws an exception if there is no such binary.*/
     fun getFramework(buildType: NativeBuildType): Framework = getFramework("", buildType)
@@ -133,7 +134,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns an Objective-C framework with the given [namePrefix] and the given build type. Returns null if there is no such binary. */
     fun findFramework(namePrefix: String, buildType: String): Framework? =
-        findFramework(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        findFramework(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns an Objective-C framework with the empty name prefix and the given build type. Returns null if there is no such binary. */
     fun findFramework(buildType: NativeBuildType): Framework? = findFramework("", buildType)
@@ -146,7 +147,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns a test executable with the given [namePrefix] and the given build type. Throws an exception if there is no such binary.*/
     fun getTest(namePrefix: String, buildType: String): TestExecutable =
-        getTest(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        getTest(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns a test executable with the empty name prefix and the given build type. Throws an exception if there is no such binary.*/
     fun getTest(buildType: NativeBuildType): TestExecutable = getTest("", buildType)
@@ -159,7 +160,7 @@ abstract class AbstractKotlinNativeBinaryContainer : DomainObjectSet<NativeBinar
 
     /** Returns a test executable with the given [namePrefix] and the given build type. Returns null if there is no such binary. */
     fun findTest(namePrefix: String, buildType: String): TestExecutable? =
-        findTest(namePrefix, NativeBuildType.valueOf(buildType.toUpperCase()))
+        findTest(namePrefix, NativeBuildType.valueOf(buildType.toUpperCaseAsciiOnly()))
 
     /** Returns a test executable with the empty name prefix and the given build type. Returns null if there is no such binary. */
     fun findTest(buildType: NativeBuildType): TestExecutable? = findTest("", buildType)
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/KaptWithoutKotlincTask.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/KaptWithoutKotlincTask.kt
index 1c68c8b55ea..76ee7e52e0f 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/KaptWithoutKotlincTask.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/KaptWithoutKotlincTask.kt
@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.gradle.internal.kapt.incremental.KaptIncrementalChan
 import org.jetbrains.kotlin.gradle.tasks.Kapt
 import org.jetbrains.kotlin.gradle.tasks.toSingleCompilerPluginOptions
 import org.jetbrains.kotlin.gradle.utils.listPropertyWithConvention
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import org.jetbrains.kotlin.utils.PathUtil
 import org.slf4j.LoggerFactory
 import java.io.File
@@ -157,7 +158,7 @@ abstract class KaptWithoutKotlincTask @Inject constructor(
         // as user may set JDK with same major Java version, but from different vendor
         val isRunningOnGradleJvm = gradleJvm.javaVersion == toolchainProvider.javaVersion.get() &&
                 gradleJvm.javaExecutable.absolutePath == toolchainProvider.javaExecutable.get().asFile.absolutePath
-        val isolationModeStr = getValue("kapt.workers.isolation")?.toLowerCase()
+        val isolationModeStr = getValue("kapt.workers.isolation")?.toLowerCaseAsciiOnly()
         return when {
             (isolationModeStr == null || isolationModeStr == "none") && isRunningOnGradleJvm -> IsolationMode.NONE
             else -> {
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/incremental/ClasspathAnalyzer.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/incremental/ClasspathAnalyzer.kt
index 79c69faed0a..ff695081f7f 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/incremental/ClasspathAnalyzer.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/internal/kapt/incremental/ClasspathAnalyzer.kt
@@ -9,6 +9,7 @@ import org.gradle.api.artifacts.transform.*
 import org.gradle.api.file.FileSystemLocation
 import org.gradle.api.provider.Provider
 import org.gradle.api.tasks.Classpath
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import org.jetbrains.org.objectweb.asm.ClassReader
 import org.jetbrains.org.objectweb.asm.ClassWriter
 import java.io.*
@@ -72,7 +73,7 @@ private fun visitDirectory(directory: File): ClasspathEntryData {
 
     directory.walk().filter {
         it.extension == "class"
-                && !it.relativeTo(directory).toString().toLowerCase().startsWith("meta-inf")
+                && !it.relativeTo(directory).toString().toLowerCaseAsciiOnly().startsWith("meta-inf")
                 && it.name != MODULE_INFO
     }.forEach {
         val internalName = it.relativeTo(directory).invariantSeparatorsPath.dropLast(".class".length)
@@ -93,7 +94,7 @@ private fun visitJar(jar: File): ClasspathEntryData {
             val entry = entries.nextElement()
 
             if (entry.name.endsWith("class")
-                && !entry.name.toLowerCase().startsWith("meta-inf")
+                && !entry.name.toLowerCaseAsciiOnly().startsWith("meta-inf")
                 && entry.name != MODULE_INFO
             ) {
                 BufferedInputStream(zipFile.getInputStream(entry)).use { inputStream ->
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTargetConfigurator.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTargetConfigurator.kt
index 1a4d18e9614..d2b2aa8c532 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTargetConfigurator.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinTargetConfigurator.kt
@@ -34,6 +34,7 @@ import org.jetbrains.kotlin.gradle.targets.jvm.KotlinJvmTarget
 import org.jetbrains.kotlin.gradle.tasks.locateOrRegisterTask
 import org.jetbrains.kotlin.gradle.tasks.registerTask
 import org.jetbrains.kotlin.gradle.utils.*
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.util.concurrent.Callable
 import kotlin.reflect.KMutableProperty1
 import kotlin.reflect.full.memberProperties
@@ -289,7 +290,7 @@ abstract class KotlinOnlyTargetConfigurator<KotlinCompilationType : KotlinCompil
         target.compilations.all { compilation ->
             buildCompilationProcessor(compilation).run()
             if (compilation.isMain()) {
-                sourcesJarTask(compilation, target.targetName, target.targetName.toLowerCase())
+                sourcesJarTask(compilation, target.targetName, target.targetName.toLowerCaseAsciiOnly())
             }
         }
     }
@@ -315,7 +316,7 @@ abstract class KotlinOnlyTargetConfigurator<KotlinCompilationType : KotlinCompil
 
         target.disambiguationClassifier?.let { classifier ->
             task.configure { taskInstance ->
-                taskInstance.archiveAppendix.set(classifier.toLowerCase())
+                taskInstance.archiveAppendix.set(classifier.toLowerCaseAsciiOnly())
             }
         }
 
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/PropertiesProvider.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/PropertiesProvider.kt
index 1c7f522511a..ff8d8e27347 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/PropertiesProvider.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/PropertiesProvider.kt
@@ -38,6 +38,8 @@ import org.jetbrains.kotlin.gradle.utils.SingleWarningPerBuild
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.konan.target.presetName
 import org.jetbrains.kotlin.statistics.metrics.StringMetrics
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toUpperCaseAsciiOnly
 import org.jetbrains.kotlin.util.prefixIfNot
 import java.io.File
 import java.util.*
@@ -434,7 +436,9 @@ internal class PropertiesProvider private constructor(private val project: Proje
         get() = this.property("kotlin.daemon.jvmargs")
 
     val kotlinCompilerExecutionStrategy: KotlinCompilerExecutionStrategy
-        get() = KotlinCompilerExecutionStrategy.fromProperty(this.property("kotlin.compiler.execution.strategy")?.toLowerCase())
+        get() = KotlinCompilerExecutionStrategy.fromProperty(
+            this.property("kotlin.compiler.execution.strategy")?.toLowerCaseAsciiOnly()
+        )
 
     val kotlinDaemonUseFallbackStrategy: Boolean
         get() = booleanProperty("kotlin.daemon.useFallbackStrategy") ?: true
@@ -460,7 +464,7 @@ internal class PropertiesProvider private constructor(private val project: Proje
     private inline fun <reified T : Enum<T>> enumProperty(
         propName: String,
         defaultValue: T
-    ): T = this.property(propName)?.let { enumValueOf<T>(it.toUpperCase()) } ?: defaultValue
+    ): T = this.property(propName)?.let { enumValueOf<T>(it.toUpperCaseAsciiOnly()) } ?: defaultValue
 
     /**
      * Looks up the property in the following sources with decreasing priority:
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/AbstractKotlinTarget.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/AbstractKotlinTarget.kt
index 93782e236d7..1a273b1c730 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/AbstractKotlinTarget.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/AbstractKotlinTarget.kt
@@ -72,7 +72,11 @@ abstract class AbstractKotlinTarget(
                 targetName
             else PRIMARY_SINGLE_COMPONENT_NAME
 
-        val sourcesArtifact = configureSourcesJarArtifact(mainCompilation, componentName, dashSeparatedName(targetName.toLowerCase()))
+        val sourcesArtifact = configureSourcesJarArtifact(
+            mainCompilation,
+            componentName,
+            dashSeparatedName(targetName.toLowerCaseAsciiOnly())
+        )
         if (sourcesArtifact != null) {
             usageContexts += DefaultKotlinUsageContext(
                 compilation = mainCompilation,
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinSoftwareComponent.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinSoftwareComponent.kt
index 28c33719e2b..0a6c13f2688 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinSoftwareComponent.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/KotlinSoftwareComponent.kt
@@ -26,6 +26,7 @@ import org.jetbrains.kotlin.gradle.targets.metadata.COMMON_MAIN_ELEMENTS_CONFIGU
 import org.jetbrains.kotlin.gradle.targets.metadata.isCompatibilityMetadataVariantEnabled
 import org.jetbrains.kotlin.gradle.targets.metadata.isKotlinGranularMetadataEnabled
 import org.jetbrains.kotlin.gradle.utils.setProperty
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 
 abstract class KotlinSoftwareComponent(
     private val project: Project,
@@ -107,7 +108,7 @@ abstract class KotlinSoftwareComponent(
             name,
             project,
             lazy { allPublishableCommonSourceSets().associate { it.name to it.kotlin } },
-            name.toLowerCase()
+            name.toLowerCaseAsciiOnly()
         )
 
     private fun addSourcesJarArtifactToConfiguration(configurationName: String): PublishArtifact {
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/apple/AppleXcodeTasks.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/apple/AppleXcodeTasks.kt
index 251ef2da140..583619a338a 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/apple/AppleXcodeTasks.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/apple/AppleXcodeTasks.kt
@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.gradle.tasks.locateOrRegisterTask
 import org.jetbrains.kotlin.gradle.tasks.registerTask
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
 import org.jetbrains.kotlin.konan.target.KonanTarget
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 
 private object XcodeEnvironment {
@@ -35,7 +36,7 @@ private object XcodeEnvironment {
         get() {
             val configuration = System.getenv("CONFIGURATION") ?: return null
 
-            fun String.toNativeBuildType() = when (this.toLowerCase()) {
+            fun String.toNativeBuildType() = when (this.toLowerCaseAsciiOnly()) {
                 "debug" -> NativeBuildType.DEBUG
                 "release" -> NativeBuildType.RELEASE
                 else -> null
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinTargetComponent.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinTargetComponent.kt
index 7f4784a64fb..2e13967e335 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinTargetComponent.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinTargetComponent.kt
@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinTargetComponentWithPublicati
 import org.jetbrains.kotlin.gradle.plugin.mpp.external.ExternalKotlinTargetComponent.TargetProvider
 import org.jetbrains.kotlin.gradle.plugin.mpp.getCoordinatesFromPublicationDelegateAndProject
 import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 
 internal class ExternalKotlinTargetComponent(
     val targetProvider: TargetProvider
@@ -45,7 +46,7 @@ internal class ExternalKotlinTargetComponent(
         get() = true
 
     override val defaultArtifactId: String
-        get() = dashSeparatedName(target.project.name, target.name.toLowerCase())
+        get() = dashSeparatedName(target.project.name, target.name.toLowerCaseAsciiOnly())
 
     @Deprecated(
         message = "Sources artifacts are now published as separate variant " +
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/kotlinVariants.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/kotlinVariants.kt
index ca627009f22..cb82d56b1c1 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/kotlinVariants.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/kotlinVariants.kt
@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.gradle.plugin.KotlinTargetComponent
 import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
 import org.jetbrains.kotlin.gradle.utils.getValue
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 
 internal interface KotlinTargetComponentWithPublication : KotlinTargetComponent {
     // This property is declared in the separate parent type to allow the usages to reference it without forcing the subtypes to load,
@@ -88,7 +89,7 @@ open class KotlinVariant(
     internal var defaultArtifactIdSuffix: String? = null
 
     override val defaultArtifactId: String
-        get() = dashSeparatedName(target.project.name, artifactTargetName.toLowerCase(), defaultArtifactIdSuffix)
+        get() = dashSeparatedName(target.project.name, artifactTargetName.toLowerCaseAsciiOnly(), defaultArtifactIdSuffix)
 
     override var publicationDelegate: MavenPublication? = null
 }
@@ -126,8 +127,8 @@ class JointAndroidKotlinTargetComponent(
     override val defaultArtifactId: String =
         dashSeparatedName(
             target.project.name,
-            target.targetName.toLowerCase(),
-            *flavorNames.map { it.toLowerCase() }.toTypedArray()
+            target.targetName.toLowerCaseAsciiOnly(),
+            *flavorNames.map { it.toLowerCaseAsciiOnly() }.toTypedArray()
         )
 
     override var publicationDelegate: MavenPublication? = null
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/variantPublishing.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/variantPublishing.kt
index fd4686628e6..0455d654e99 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/variantPublishing.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/pm20/variantPublishing.kt
@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.gradle.plugin.mpp.publishedConfigurationName
 import org.jetbrains.kotlin.gradle.plugin.usageByName
 import org.jetbrains.kotlin.gradle.tasks.withType
 import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.util.*
 import javax.inject.Inject
 
@@ -192,7 +193,7 @@ open class GradleKpmVariantPublishingConfigurator @Inject constructor(
                         publishedModuleHolder.assignMavenPublication(this)
                         artifactId = dashSeparatedName(
                             project.name, publishedModuleHolder.defaultPublishedModuleSuffix
-                        ).toLowerCase(Locale.ENGLISH)
+                        ).toLowerCaseAsciiOnly()
                     }
                 }
             }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/report/configureReporing.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/report/configureReporing.kt
index abe3221c2a9..d8eee5bed06 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/report/configureReporing.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/report/configureReporing.kt
@@ -9,11 +9,12 @@ import org.gradle.api.Project
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLIN_BUILD_REPORT_SINGLE_FILE
 import org.jetbrains.kotlin.gradle.plugin.PropertiesProvider.PropertyNames.KOTLIN_BUILD_REPORT_HTTP_URL
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toUpperCaseAsciiOnly
 
 internal fun reportingSettings(rootProject: Project): ReportingSettings {
     val properties = PropertiesProvider(rootProject)
     val buildReportOutputTypes = properties.buildReportOutputs.map {
-        BuildReportType.values().firstOrNull { brt -> brt.name == it.trim().toUpperCase() }
+        BuildReportType.values().firstOrNull { brt -> brt.name == it.trim().toUpperCaseAsciiOnly() }
             ?: throw IllegalStateException("Unknown output type: $it")
     }.toMutableList() //temporary solution. support old property
     val buildReportMode =
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/KotlinAndroidTarget.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/KotlinAndroidTarget.kt
index 2e1de42022e..e24a9a32935 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/KotlinAndroidTarget.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/android/KotlinAndroidTarget.kt
@@ -19,6 +19,7 @@ import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
 import org.jetbrains.kotlin.gradle.utils.forAllAndroidVariants
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
 import org.jetbrains.kotlin.gradle.utils.setProperty
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import javax.inject.Inject
 
 abstract class KotlinAndroidTarget @Inject constructor(
@@ -138,7 +139,7 @@ abstract class KotlinAndroidTarget @Inject constructor(
                         defaultArtifactIdSuffix =
                             dashSeparatedName(
                                 (getFlavorNames(androidVariant) + getBuildTypeName(androidVariant).takeIf { it != "release" })
-                                    .map { it?.toLowerCase() }
+                                    .map { it?.toLowerCaseAsciiOnly() }
                             ).takeIf { it.isNotEmpty() }
                     }
                 }
@@ -191,9 +192,9 @@ abstract class KotlinAndroidTarget @Inject constructor(
             compilation,
             compilation.disambiguateName(""),
             dashSeparatedName(
-                compilation.target.name.toLowerCase(),
-                *flavorNames.map { it.toLowerCase() }.toTypedArray(),
-                buildTypeName.takeIf { it != "release" }?.toLowerCase()
+                compilation.target.name.toLowerCaseAsciiOnly(),
+                *flavorNames.map { it.toLowerCaseAsciiOnly() }.toTypedArray(),
+                buildTypeName.takeIf { it != "release" }?.toLowerCaseAsciiOnly()
             ),
             classifierPrefix = artifactClassifier,
             sourcesElementsConfigurationName = sourcesElementsConfigurationName
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/KotlinJsTarget.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/KotlinJsTarget.kt
index a4a4a6e8013..093246d84f5 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/KotlinJsTarget.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/KotlinJsTarget.kt
@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.gradle.testing.testTaskName
 import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
 import org.jetbrains.kotlin.gradle.utils.setProperty
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import javax.inject.Inject
 
 abstract class KotlinJsTarget
@@ -80,7 +81,7 @@ constructor(
                     irTarget?.let { targetName.removeJsCompilerSuffix(LEGACY) } ?: targetName
                 else PRIMARY_SINGLE_COMPONENT_NAME
 
-            configureSourcesJarArtifact(mainCompilation, componentName, dashSeparatedName(targetName.toLowerCase()))
+            configureSourcesJarArtifact(mainCompilation, componentName, dashSeparatedName(targetName.toLowerCaseAsciiOnly()))
             usageContexts += DefaultKotlinUsageContext(
                 compilation = mainCompilation,
                 mavenScope = KotlinUsageContext.MavenScope.RUNTIME,
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/binaryen/BinaryenPlatform.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/binaryen/BinaryenPlatform.kt
index eb2532e8163..e5db7cc50a3 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/binaryen/BinaryenPlatform.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/binaryen/BinaryenPlatform.kt
@@ -1,5 +1,7 @@
 package org.jetbrains.kotlin.gradle.targets.js.binaryen
 
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
+
 /**
  * Provides platform and architecture names that is used to download Binaryen.
  */
@@ -12,7 +14,7 @@ internal object BinaryenPlatform {
     const val DARWIN = "macos"
 
     val name: String = run {
-        val name = property("os.name").toLowerCase()
+        val name = property("os.name").toLowerCaseAsciiOnly()
         when {
             name.contains("windows") -> WIN
             name.contains("mac") -> DARWIN
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinBrowserJsIr.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinBrowserJsIr.kt
index 46670b88822..eefafc1974a 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinBrowserJsIr.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinBrowserJsIr.kt
@@ -28,6 +28,7 @@ import org.jetbrains.kotlin.gradle.targets.js.webpack.WebpackMajorVersion.Compan
 import org.jetbrains.kotlin.gradle.tasks.dependsOn
 import org.jetbrains.kotlin.gradle.utils.doNotTrackStateCompat
 import org.jetbrains.kotlin.gradle.utils.newFileProperty
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 import javax.inject.Inject
 
@@ -129,7 +130,7 @@ abstract class KotlinBrowserJsIr @Inject constructor(target: KotlinJsIrTarget) :
                         { task.args.add(0, "serve") },
                         { task.bin = "webpack-dev-server/bin/webpack-dev-server.js" }
                     )()
-                    task.description = "start ${mode.name.toLowerCase()} webpack dev server"
+                    task.description = "start ${mode.name.toLowerCaseAsciiOnly()} webpack dev server"
 
                     webpackMajorVersion.choose(
                         {
@@ -210,7 +211,7 @@ abstract class KotlinBrowserJsIr @Inject constructor(target: KotlinJsIrTarget) :
                             .resolve(link.compilerOptions.moduleName.get() + ".js")
                     }
 
-                    task.description = "build webpack ${mode.name.toLowerCase()} bundle"
+                    task.description = "build webpack ${mode.name.toLowerCaseAsciiOnly()} bundle"
                     task._destinationDirectory = binary.distribution.directory
 
                     BuildMetricsService.registerIfAbsent(project)?.let {
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsBinaryContainer.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsBinaryContainer.kt
index f3b24385872..948ff905e6b 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsBinaryContainer.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsBinaryContainer.kt
@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.gradle.targets.js.dsl.KotlinJsBinaryMode.PRODUCTION
 import org.jetbrains.kotlin.gradle.targets.js.subtargets.DefaultDistribution
 import org.jetbrains.kotlin.gradle.targets.js.subtargets.KotlinJsSubTarget
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import javax.inject.Inject
 
 open class KotlinJsBinaryContainer
@@ -216,8 +217,8 @@ constructor(
         ) =
             lowerCamelCaseName(
                 if (compilation.isMain()) null else compilation.name,
-                mode.name.toLowerCase(),
-                jsBinaryType?.name?.toLowerCase()
+                mode.name.toLowerCaseAsciiOnly(),
+                jsBinaryType?.name?.toLowerCaseAsciiOnly()
             )
     }
 }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrLink.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrLink.kt
index 504d4833bb4..3985fa7e674 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrLink.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrLink.kt
@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.gradle.targets.js.dsl.KotlinJsBinaryMode.DEVELOPMENT
 import org.jetbrains.kotlin.gradle.tasks.Kotlin2JsCompile
 import org.jetbrains.kotlin.statistics.metrics.BooleanMetrics
 import org.jetbrains.kotlin.statistics.metrics.StringMetrics
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import javax.inject.Inject
 
 @CacheableTask
@@ -107,9 +108,9 @@ abstract class KotlinJsIrLink @Inject constructor(
             it.report(
                 StringMetrics.JS_OUTPUT_GRANULARITY,
                 if (newArgs.irPerModule)
-                    KotlinJsIrOutputGranularity.PER_MODULE.name.toLowerCase()
+                    KotlinJsIrOutputGranularity.PER_MODULE.name.toLowerCaseAsciiOnly()
                 else
-                    KotlinJsIrOutputGranularity.WHOLE_PROGRAM.name.toLowerCase()
+                    KotlinJsIrOutputGranularity.WHOLE_PROGRAM.name.toLowerCaseAsciiOnly()
             )
         }
 
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrSubTargetBase.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrSubTargetBase.kt
index 39eb420cf7e..6c5f0b8820c 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrSubTargetBase.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/ir/KotlinJsIrSubTargetBase.kt
@@ -8,6 +8,7 @@ package org.jetbrains.kotlin.gradle.targets.js.ir
 import org.gradle.language.base.plugins.LifecycleBasePlugin
 import org.jetbrains.kotlin.gradle.targets.js.dsl.KotlinJsBinaryMode
 import org.jetbrains.kotlin.gradle.tasks.dependsOn
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 
 abstract class KotlinJsIrSubTargetBase(target: KotlinJsIrTarget, classifier: String) :
     KotlinJsIrSubTarget(target, classifier) {
@@ -25,7 +26,7 @@ abstract class KotlinJsIrSubTargetBase(target: KotlinJsIrTarget, classifier: Str
 
     private fun configureRun(binary: JsIrBinary) {
         val binaryRunName = disambiguateCamelCased(
-            binary.mode.name.toLowerCase(),
+            binary.mode.name.toLowerCaseAsciiOnly(),
             RUN_TASK_NAME
         )
 
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/nodejs/NodeJsPlatform.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/nodejs/NodeJsPlatform.kt
index 44ac336c1fa..04178263b74 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/nodejs/NodeJsPlatform.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/nodejs/NodeJsPlatform.kt
@@ -1,5 +1,7 @@
 package org.jetbrains.kotlin.gradle.targets.js.nodejs
 
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
+
 /**
  * Provides platform and architecture names that is used to download NodeJs.
  * See [NodeJsEnv.ivyDependency] that is filled in [NodeJsRootExtension.environment].
@@ -14,7 +16,7 @@ internal object NodeJsPlatform {
     const val SUNOS = "sunos"
 
     val name: String = run {
-        val name = property("os.name").toLowerCase()
+        val name = property("os.name").toLowerCaseAsciiOnly()
         when {
             name.contains("windows") -> WIN
             name.contains("mac") -> DARWIN
@@ -30,7 +32,7 @@ internal object NodeJsPlatform {
     const val ARM64 = "arm64"
 
     val architecture: String = run {
-        val arch = property("os.arch").toLowerCase()
+        val arch = property("os.arch").toLowerCaseAsciiOnly()
         when {
             arch == "aarch64" -> ARM64
             arch.contains("64") -> X64
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmDependencyExtension.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmDependencyExtension.kt
index a556d84c143..6b8954c4bc2 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmDependencyExtension.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmDependencyExtension.kt
@@ -13,6 +13,7 @@ import org.gradle.api.reflect.TypeOf
 import org.jetbrains.kotlin.gradle.plugin.warnNpmGenerateExternals
 import org.jetbrains.kotlin.gradle.targets.js.npm.NpmDependency.Scope.*
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 
 interface BaseNpmDependencyExtension {
@@ -100,7 +101,7 @@ internal fun Project.addNpmDependencyExtension() {
 private fun scopePrefix(scope: NpmDependency.Scope): String {
     val scopePrefix = scope.name
         .removePrefix(NORMAL.name)
-        .toLowerCase()
+        .toLowerCaseAsciiOnly()
 
     return lowerCamelCaseName(scopePrefix, "npm")
 }
@@ -182,7 +183,7 @@ private abstract class NpmDependencyExtensionDelegate(
     protected fun npmDeclarationException(args: Array<out Any?>): Nothing {
         throw IllegalArgumentException(
             """
-            |Unable to add NPM dependency with scope '${scope.name.toLowerCase()}' by ${args.joinToString { "'$it'" }}
+            |Unable to add NPM dependency with scope '${scope.name.toLowerCaseAsciiOnly()}' by ${args.joinToString { "'$it'" }}
             |Possible variants:
             |${possibleVariants().joinToString("\n") { "- ${it.first} -> ${it.second}" }}
             """.trimMargin()
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt
index 2fdcb3a4647..1cb7cd7b705 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/NpmProject.kt
@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.gradle.plugin.mpp.disambiguateName
 import org.jetbrains.kotlin.gradle.targets.js.dsl.KotlinJsTargetDsl
 import org.jetbrains.kotlin.gradle.targets.js.nodejs.NodeJsRootPlugin
 import org.jetbrains.kotlin.gradle.targets.js.npm.tasks.KotlinPackageJsonTask
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 import java.io.Serializable
 
@@ -129,14 +130,14 @@ open class NpmProject(@Transient val compilation: KotlinJsCompilation) : Seriali
             project.name
         } else null
 
-        val targetName = if (target.name.isNotEmpty() && target.name.toLowerCase() != "js") {
+        val targetName = if (target.name.isNotEmpty() && target.name.toLowerCaseAsciiOnly() != "js") {
             target.name
                 .replace(DECAMELIZE_REGEX) {
                     it.groupValues
                         .drop(1)
                         .joinToString(prefix = "-", separator = "-")
                 }
-                .toLowerCase()
+                .toLowerCaseAsciiOnly()
         } else null
 
         return sequenceOf(
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinBrowserJs.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinBrowserJs.kt
index fb06e920db3..8408e8d1a33 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinBrowserJs.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/subtargets/KotlinBrowserJs.kt
@@ -34,6 +34,7 @@ import org.jetbrains.kotlin.gradle.tasks.dependsOn
 import org.jetbrains.kotlin.gradle.tasks.registerTask
 import org.jetbrains.kotlin.gradle.utils.doNotTrackStateCompat
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 import javax.inject.Inject
 import org.jetbrains.kotlin.gradle.tasks.KotlinJsDce as KotlinJsDceTask
@@ -153,7 +154,7 @@ abstract class KotlinBrowserJs @Inject constructor(target: KotlinJsTarget) :
                         { task.bin = "webpack-dev-server/bin/webpack-dev-server.js" }
                     )()
 
-                    task.description = "start ${type.name.toLowerCase()} webpack dev server"
+                    task.description = "start ${type.name.toLowerCaseAsciiOnly()} webpack dev server"
 
                     webpackMajorVersion.choose(
                         {
@@ -235,7 +236,7 @@ abstract class KotlinBrowserJs @Inject constructor(target: KotlinJsTarget) :
                         distributeResourcesTask
                     )
 
-                    task.description = "build webpack ${type.name.toLowerCase()} bundle"
+                    task.description = "build webpack ${type.name.toLowerCaseAsciiOnly()} bundle"
                     task._destinationDirectory = distribution.directory
 
                     BuildMetricsService.registerIfAbsent(project)?.let {
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
index 37651f1c463..9b00cd4ff84 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
@@ -37,6 +37,7 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinTest
 import org.jetbrains.kotlin.gradle.testing.internal.reportsDir
 import org.jetbrains.kotlin.gradle.utils.appendLine
 import org.jetbrains.kotlin.gradle.utils.property
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import org.slf4j.Logger
 import java.io.File
 
@@ -106,7 +107,7 @@ class KotlinKarma(
         val propValue = project.kotlinPropertiesProvider.jsKarmaBrowsers(compilation.target)
         val propBrowsers = propValue?.split(",")
         propBrowsers?.map(String::trim)?.forEach {
-            when (it.toLowerCase()) {
+            when (it.toLowerCaseAsciiOnly()) {
                 "chrome" -> useChrome()
                 "chrome-canary" -> useChromeCanary()
                 "chrome-canary-headless" -> useChromeCanaryHeadless()
@@ -503,7 +504,7 @@ class KotlinKarma(
 
                         val actualText = if (launcherMessage != null) {
                             val (logLevel, message) = launcherMessage.destructured
-                            actualType = LogType.byValueOrNull(logLevel.toLowerCase())
+                            actualType = LogType.byValueOrNull(logLevel.toLowerCaseAsciiOnly())
                             if (actualType?.isErrorLike() == true) {
                                 processFailedBrowsers(text)
                             }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTarget.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTarget.kt
index 36e95ecfb8b..0e12a71a855 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTarget.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTarget.kt
@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.gradle.tasks.locateOrRegisterTask
 import org.jetbrains.kotlin.gradle.utils.dashSeparatedName
 import org.jetbrains.kotlin.konan.target.HostManager
 import org.jetbrains.kotlin.konan.target.KonanTarget
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import javax.inject.Inject
 
 abstract class KotlinNativeTarget @Inject constructor(
@@ -60,7 +61,7 @@ abstract class KotlinNativeTarget @Inject constructor(
 
             if (hostSpecificSourceSets.isNotEmpty()) {
                 val hostSpecificMetadataJar = project.locateOrRegisterTask<Jar>(hostSpecificMetadataJarTaskName) { metadataJar ->
-                    metadataJar.archiveAppendix.set(project.provider { disambiguationClassifier.orEmpty().toLowerCase() })
+                    metadataJar.archiveAppendix.set(project.provider { disambiguationClassifier.orEmpty().toLowerCaseAsciiOnly() })
                     metadataJar.archiveClassifier.set("metadata")
                     metadataJar.group = BasePlugin.BUILD_GROUP
                     metadataJar.description = "Assembles Kotlin metadata of target '${name}'."
@@ -101,7 +102,7 @@ abstract class KotlinNativeTarget @Inject constructor(
             }
         }
 
-        configureSourcesJarArtifact(mainCompilation, targetName, dashSeparatedName(targetName.toLowerCase()))
+        configureSourcesJarArtifact(mainCompilation, targetName, dashSeparatedName(targetName.toLowerCaseAsciiOnly()))
         val sourcesUsage = DefaultKotlinUsageContext(
             compilation = mainCompilation,
             dependencyConfigurationName = sourcesElementsConfigurationName,
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTargetConfigurator.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTargetConfigurator.kt
index e3e9bd06102..df8deb20dad 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTargetConfigurator.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/KotlinNativeTargetConfigurator.kt
@@ -47,6 +47,7 @@ import org.jetbrains.kotlin.gradle.utils.*
 import org.jetbrains.kotlin.konan.target.HostManager
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.util.capitalizeDecapitalize.capitalizeAsciiOnly
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 
 open class KotlinNativeTargetConfigurator<T : KotlinNativeTarget> : AbstractKotlinTargetConfigurator<T>(
@@ -144,7 +145,11 @@ open class KotlinNativeTargetConfigurator<T : KotlinNativeTarget> : AbstractKotl
         }
 
         fun configureFatFramework() {
-            val fatFrameworkConfigurationName = lowerCamelCaseName(binary.name, binary.target.konanTarget.family.name.toLowerCase(), "fat")
+            val fatFrameworkConfigurationName = lowerCamelCaseName(
+                binary.name,
+                binary.target.konanTarget.family.name.toLowerCaseAsciiOnly(),
+                "fat"
+            )
             val fatFrameworkTaskName = "link${fatFrameworkConfigurationName.capitalizeAsciiOnly()}"
 
             val fatFrameworkTask = if (fatFrameworkTaskName in tasks.names) {
@@ -152,7 +157,7 @@ open class KotlinNativeTargetConfigurator<T : KotlinNativeTarget> : AbstractKotl
             } else {
                 tasks.register(fatFrameworkTaskName, FatFrameworkTask::class.java) {
                     it.baseName = binary.baseName
-                    it.destinationDir = it.destinationDir.resolve(binary.buildType.name.toLowerCase())
+                    it.destinationDir = it.destinationDir.resolve(binary.buildType.name.toLowerCaseAsciiOnly())
                 }
             }
 
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/NativeBinaries.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/NativeBinaries.kt
index c103d6bc5ed..00077d81f2e 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/NativeBinaries.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/NativeBinaries.kt
@@ -22,6 +22,7 @@ import org.jetbrains.kotlin.gradle.tasks.KotlinNativeLink
 import org.jetbrains.kotlin.gradle.utils.Xcode
 import org.jetbrains.kotlin.gradle.utils.lowerCamelCaseName
 import org.jetbrains.kotlin.konan.target.KonanTarget
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toUpperCaseAsciiOnly
 import java.io.File
 
 /**
@@ -310,7 +311,7 @@ class Framework(
      *     marker - Embed placeholder LLVM IR data as a marker.
      *              Has the same effect as the -Xembed-bitcode-marker command line option.
      */
-    fun embedBitcode(mode: String) = embedBitcode(org.jetbrains.kotlin.gradle.plugin.mpp.BitcodeEmbeddingMode.valueOf(mode.toUpperCase()))
+    fun embedBitcode(mode: String) = embedBitcode(org.jetbrains.kotlin.gradle.plugin.mpp.BitcodeEmbeddingMode.valueOf(mode.toUpperCaseAsciiOnly()))
 
     /**
      * Specifies if the framework is linked as a static library (false by default).
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/NativeDistributionType.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/NativeDistributionType.kt
index 0140d5efd86..0bb97da0fba 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/NativeDistributionType.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/internal/NativeDistributionType.kt
@@ -12,6 +12,7 @@ import org.jetbrains.kotlin.gradle.targets.native.internal.NativeDistributionTyp
 import org.jetbrains.kotlin.gradle.utils.SingleWarningPerBuild
 import org.jetbrains.kotlin.konan.CompilerVersion
 import org.jetbrains.kotlin.konan.target.HostManager
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 
 internal enum class NativeDistributionType(val suffix: String?, val mustGeneratePlatformLibs: Boolean) {
     LIGHT(null, true),
@@ -32,7 +33,7 @@ internal class NativeDistributionTypeProvider(private val project: Project) {
         lightType: NativeDistributionType,
         defaultType: NativeDistributionType
     ): NativeDistributionType {
-        val requestedByUser = propertiesProvider.nativeDistributionType?.toLowerCase()
+        val requestedByUser = propertiesProvider.nativeDistributionType?.toLowerCaseAsciiOnly()
         val deprecatedRestricted = propertiesProvider.nativeDeprecatedRestricted
 
         // A case when a deprecated property (kotlin.native.restrictedDistribution) is used to choose the restricted distribution.
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/AdvancedCocoapodsTasks.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/AdvancedCocoapodsTasks.kt
index 87f7fd749a8..fee5fabc73e 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/AdvancedCocoapodsTasks.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/AdvancedCocoapodsTasks.kt
@@ -25,6 +25,7 @@ import org.jetbrains.kotlin.gradle.tasks.PodspecTask.Companion.retrieveSpecRepos
 import org.jetbrains.kotlin.gradle.utils.runCommand
 import org.jetbrains.kotlin.konan.target.Family
 import org.jetbrains.kotlin.konan.target.HostManager
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 import java.io.IOException
 import java.io.Reader
@@ -491,11 +492,11 @@ private object CocoapodsErrorHandlingUtil {
         ) {
             message += """
                 |
-                |        Possible reason: ${family.name.toLowerCase()} deployment target is not configured
+                |        Possible reason: ${family.name.toLowerCaseAsciiOnly()} deployment target is not configured
                 |        Configure deployment_target for ALL targets as follows:
                 |        cocoapods {
                 |           ...
-                |           ${family.name.toLowerCase()}.deploymentTarget = "..."
+                |           ${family.name.toLowerCaseAsciiOnly()}.deploymentTarget = "..."
                 |           ...
                 |        }
                 |       
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/FatFrameworkTask.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/FatFrameworkTask.kt
index a0b29375941..0058af3f7fd 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/FatFrameworkTask.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/FatFrameworkTask.kt
@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.konan.target.HostManager
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.konan.target.KonanTarget.*
 import org.jetbrains.kotlin.konan.util.visibleName
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.ByteArrayOutputStream
 import java.io.File
 import java.nio.file.Files
@@ -227,7 +228,7 @@ internal constructor(
 
             require(!archToFramework.containsKey(arch)) {
                 val alreadyAdded = archToFramework.getValue(arch)
-                "This fat framework already has a binary for architecture `${arch.name.toLowerCase()}` " +
+                "This fat framework already has a binary for architecture `${arch.name.toLowerCaseAsciiOnly()}` " +
                         "(${alreadyAdded.name} for target `${alreadyAdded.target.name}`)"
             }
 
@@ -236,8 +237,10 @@ internal constructor(
 
                 buildString {
                     append("Cannot create a fat framework from:\n")
-                    archToFramework.forEach { append("${it.value.name} - ${it.key.name.toLowerCase()} - ${staticName(it.value.isStatic)}\n") }
-                    append("${framework.name} - ${arch.name.toLowerCase()} - ${staticName(framework.isStatic)}\n")
+                    archToFramework.forEach {
+                        append("${it.value.name} - ${it.key.name.toLowerCaseAsciiOnly()} - ${staticName(it.value.isStatic)}\n")
+                    }
+                    append("${framework.name} - ${arch.name.toLowerCaseAsciiOnly()} - ${staticName(framework.isStatic)}\n")
                     append("All input frameworks must be either static or dynamic")
                 }
             }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/KotlinNativeCompilerArgBuilder.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/KotlinNativeCompilerArgBuilder.kt
index f0b0b359e88..cab23480832 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/KotlinNativeCompilerArgBuilder.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/targets/native/tasks/KotlinNativeCompilerArgBuilder.kt
@@ -14,6 +14,7 @@ import org.jetbrains.kotlin.gradle.tasks.CompilerPluginOptions
 import org.jetbrains.kotlin.konan.target.CompilerOutputKind
 import org.jetbrains.kotlin.konan.target.KonanTarget
 import org.jetbrains.kotlin.project.model.LanguageSettings
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.io.File
 
 internal class CompilerPluginData(
@@ -138,7 +139,7 @@ private fun buildKotlinNativeMainArgs(
     addKey("-g", debuggable)
     addKey("-ea", debuggable)
     addArg("-target", target.name)
-    addArg("-p", outputKind.name.toLowerCase())
+    addArg("-p", outputKind.name.toLowerCaseAsciiOnly())
     addArg("-o", outFile.absolutePath)
     libraries.forEach { addArg("-l", it.absolutePath) }
 }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/utils/stringUtils.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/utils/stringUtils.kt
index 7120575b533..42c89853a6c 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/utils/stringUtils.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/utils/stringUtils.kt
@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.gradle.utils
 
 import org.jetbrains.kotlin.util.capitalizeDecapitalize.capitalizeAsciiOnly
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import java.util.*
 
 internal fun lowerCamelCaseName(vararg nameParts: String?): String {
@@ -28,14 +29,14 @@ internal fun dashSeparatedLowercaseName(nameParts: Iterable<String?>) =
     dashSeparatedLowercaseName(*nameParts.toList().toTypedArray())
 
 internal fun dashSeparatedLowercaseName(vararg nameParts: String?): String {
-    val nonEmptyParts = nameParts.mapNotNull { it?.takeIf(String::isNotEmpty)?.toLowerCase(Locale.ENGLISH) }
+    val nonEmptyParts = nameParts.mapNotNull { it?.takeIf(String::isNotEmpty)?.toLowerCaseAsciiOnly() }
     return nonEmptyParts.joinToString(separator = "-")
 }
 
 internal fun String.decamelize(): String {
     return replace(upperCaseRegex) {
         val (first) = it.destructured
-        "-${first.toLowerCase()}"
+        "-${first.toLowerCaseAsciiOnly()}"
     }
 }
 
diff --git a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/JvmAndAndroidIntermediateSourceSetTest.kt b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/JvmAndAndroidIntermediateSourceSetTest.kt
index ac7c17417b9..253e7dc2346 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/JvmAndAndroidIntermediateSourceSetTest.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/JvmAndAndroidIntermediateSourceSetTest.kt
@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinAndroidTarget
 import org.jetbrains.kotlin.gradle.plugin.mpp.KotlinMetadataCompilation
 import org.jetbrains.kotlin.gradle.plugin.mpp.kotlinProjectStructureMetadata
+import org.jetbrains.kotlin.util.capitalizeDecapitalize.toLowerCaseAsciiOnly
 import kotlin.test.*
 
 class JvmAndAndroidIntermediateSourceSetTest {
@@ -117,7 +118,7 @@ class JvmAndAndroidIntermediateSourceSetTest {
         assertTrue(kotlinComponents.isNotEmpty(), "Expected at least one KotlinComponent to be present")
 
         kotlinComponents.forEach { component ->
-            val isReleaseComponent = "release" in component.name.toLowerCase()
+            val isReleaseComponent = "release" in component.name.toLowerCaseAsciiOnly()
             if (isReleaseComponent) {
                 assertTrue(component.publishable, "Expected release component to be marked as publishable")
             } else {