diff --git a/build.gradle.kts b/build.gradle.kts
index d9cddba45c9..50a70933fa8 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -351,7 +351,7 @@ allprojects {
     configureJvmProject(javaHome!!, jvmTarget!!)
 
     val commonCompilerArgs = listOfNotNull(
-        "-Xuse-experimental=kotlin.Experimental",
+        "-Xopt-in=kotlin.RequiresOptIn",
         "-Xread-deserialized-contracts",
         "-Xjvm-default=compatibility",
         "-progressive".takeIf { hasProperty("test.progressive.mode") }
diff --git a/libraries/kotlin.test/common/build.gradle b/libraries/kotlin.test/common/build.gradle
index 6e3a9d47516..057fa80468b 100644
--- a/libraries/kotlin.test/common/build.gradle
+++ b/libraries/kotlin.test/common/build.gradle
@@ -32,7 +32,7 @@ compileKotlinCommon {
     kotlinOptions {
         freeCompilerArgs += [
                 "-module-name", project.name,
-                "-Xuse-experimental=kotlin.contracts.ExperimentalContracts"
+                "-Xopt-in=kotlin.contracts.ExperimentalContracts",
         ]
     }
 }
diff --git a/libraries/kotlin.test/js/build.gradle b/libraries/kotlin.test/js/build.gradle
index 4c7d16974f2..eaf07572b71 100644
--- a/libraries/kotlin.test/js/build.gradle
+++ b/libraries/kotlin.test/js/build.gradle
@@ -19,7 +19,7 @@ dependencies {
 compileKotlin2Js {
     kotlinOptions.freeCompilerArgs = [
             "-Xallow-kotlin-package",
-            "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+            "-Xopt-in=kotlin.contracts.ExperimentalContracts",
     ]
     kotlinOptions {
         moduleKind = "umd"
diff --git a/libraries/kotlin.test/jvm/build.gradle b/libraries/kotlin.test/jvm/build.gradle
index 7d773a2a67e..e8f4b658149 100644
--- a/libraries/kotlin.test/jvm/build.gradle
+++ b/libraries/kotlin.test/jvm/build.gradle
@@ -49,7 +49,7 @@ javadocJar()
 
 compileKotlin {
     kotlinOptions.freeCompilerArgs = ["-Xallow-kotlin-package", "-Xnormalize-constructor-calls=enable",
-                                      "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+                                      "-Xopt-in=kotlin.contracts.ExperimentalContracts",
                                       "-module-name", project.archivesBaseName, ]
 }
 
diff --git a/libraries/stdlib/common/build.gradle b/libraries/stdlib/common/build.gradle
index 4b06a753d1d..6e3553bf6b1 100644
--- a/libraries/stdlib/common/build.gradle
+++ b/libraries/stdlib/common/build.gradle
@@ -38,9 +38,9 @@ compileKotlinCommon {
     kotlinOptions {
         freeCompilerArgs = [
                 "-module-name", project.name,
-                "-Xuse-experimental=kotlin.Experimental",
-                "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-                "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+                "-Xopt-in=kotlin.RequiresOptIn",
+                "-Xopt-in=kotlin.ExperimentalMultiplatform",
+                "-Xopt-in=kotlin.contracts.ExperimentalContracts",
                 "-Xinline-classes",
                 "-Xallow-kotlin-package",
                 "-Xallow-result-return-type"
@@ -51,9 +51,9 @@ compileKotlinCommon {
 compileTestKotlinCommon {
     kotlinOptions {
         freeCompilerArgs += [
-                "-Xuse-experimental=kotlin.Experimental",
-                "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-                "-Xuse-experimental=kotlin.ExperimentalStdlibApi"
+                "-Xopt-in=kotlin.RequiresOptIn",
+                "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
+                "-Xopt-in=kotlin.ExperimentalStdlibApi",
         ]
     }
 }
diff --git a/libraries/stdlib/coroutines-experimental/build.gradle.kts b/libraries/stdlib/coroutines-experimental/build.gradle.kts
index 903d171b364..250ff4677bb 100644
--- a/libraries/stdlib/coroutines-experimental/build.gradle.kts
+++ b/libraries/stdlib/coroutines-experimental/build.gradle.kts
@@ -48,8 +48,8 @@ tasks {
                 "-Xmulti-platform",
                 "-Xallow-kotlin-package",
                 "-Xmultifile-parts-inherit",
-                "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
-                "-Xuse-experimental=kotlin.Experimental",
+                "-Xopt-in=kotlin.RequiresOptIn",
+                "-Xopt-in=kotlin.contracts.ExperimentalContracts",
                 "-Xcoroutines=enable",
                 "-XXLanguage:-ReleaseCoroutines",
                 "-Xno-use-ir",
diff --git a/libraries/stdlib/jdk7/build.gradle b/libraries/stdlib/jdk7/build.gradle
index 92d8287e9ea..6ec332659b9 100644
--- a/libraries/stdlib/jdk7/build.gradle
+++ b/libraries/stdlib/jdk7/build.gradle
@@ -79,7 +79,7 @@ compileKotlin {
             "-Xmultifile-parts-inherit",
             "-Xnormalize-constructor-calls=enable",
             "-module-name", project.name,
-            "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+            "-Xopt-in=kotlin.contracts.ExperimentalContracts",
     ]
 }
 
@@ -87,9 +87,9 @@ compileTestKotlin {
     kotlinOptions.freeCompilerArgs = [
             "-Xallow-kotlin-package",
             "-Xmulti-platform",
-            "-Xuse-experimental=kotlin.Experimental",
-            "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-            "-Xuse-experimental=kotlin.ExperimentalStdlibApi"
+            "-Xopt-in=kotlin.RequiresOptIn",
+            "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
+            "-Xopt-in=kotlin.ExperimentalStdlibApi",
     ]
 }
 
diff --git a/libraries/stdlib/jdk8/build.gradle b/libraries/stdlib/jdk8/build.gradle
index a5dbf4f0296..4da11ac0021 100644
--- a/libraries/stdlib/jdk8/build.gradle
+++ b/libraries/stdlib/jdk8/build.gradle
@@ -81,9 +81,9 @@ compileTestKotlin {
     kotlinOptions.freeCompilerArgs = [
             "-Xallow-kotlin-package",
             "-Xmulti-platform",
-            "-Xuse-experimental=kotlin.Experimental",
-            "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-            "-Xuse-experimental=kotlin.ExperimentalStdlibApi"
+            "-Xopt-in=kotlin.RequiresOptIn",
+            "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
+            "-Xopt-in=kotlin.ExperimentalStdlibApi",
     ]
 }
 
diff --git a/libraries/stdlib/js-ir/build.gradle.kts b/libraries/stdlib/js-ir/build.gradle.kts
index f71285104d5..a8f6b911534 100644
--- a/libraries/stdlib/js-ir/build.gradle.kts
+++ b/libraries/stdlib/js-ir/build.gradle.kts
@@ -279,11 +279,11 @@ fun JavaExec.buildJs(sources: List<String>, dependencies: List<String>, outPath:
      sources.toList() + listOf("-output", outPath) + libraryArgs + listOf(
          "-Xir-produce-js",
          "-Xmulti-platform",
-         "-Xuse-experimental=kotlin.Experimental",
-         "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
-         "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-         "-Xuse-experimental=kotlin.ExperimentalStdlibApi",
-         "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes"
+         "-Xopt-in=kotlin.RequiresOptIn",
+         "-Xopt-in=kotlin.contracts.ExperimentalContracts",
+         "-Xopt-in=kotlin.ExperimentalMultiplatform",
+         "-Xopt-in=kotlin.ExperimentalStdlibApi",
+         "-Xopt-in=kotlin.ExperimentalUnsignedTypes"
      )
     args = allArgs
 
diff --git a/libraries/stdlib/js-v1/build.gradle b/libraries/stdlib/js-v1/build.gradle
index 17a92f75f25..f51903e060c 100644
--- a/libraries/stdlib/js-v1/build.gradle
+++ b/libraries/stdlib/js-v1/build.gradle
@@ -141,9 +141,9 @@ compileKotlin2Js {
                         .collect { file(it).absoluteFile }
         )
         freeCompilerArgs += [
-            "-Xuse-experimental=kotlin.Experimental",
-            "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-            "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+            "-Xopt-in=kotlin.RequiresOptIn",
+            "-Xopt-in=kotlin.ExperimentalMultiplatform",
+            "-Xopt-in=kotlin.contracts.ExperimentalContracts",
             "-Xinline-classes"
         ]
     }
@@ -153,9 +153,9 @@ compileTestKotlin2Js {
     kotlinOptions {
         moduleKind = "umd"
         freeCompilerArgs += [
-            "-Xuse-experimental=kotlin.Experimental",
-            "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-            "-Xuse-experimental=kotlin.ExperimentalStdlibApi"
+            "-Xopt-in=kotlin.RequiresOptIn",
+            "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
+            "-Xopt-in=kotlin.ExperimentalStdlibApi",
         ]
     }
 }
diff --git a/libraries/stdlib/jvm-minimal-for-test/build.gradle.kts b/libraries/stdlib/jvm-minimal-for-test/build.gradle.kts
index 58a44c8730e..c7d2911b4db 100644
--- a/libraries/stdlib/jvm-minimal-for-test/build.gradle.kts
+++ b/libraries/stdlib/jvm-minimal-for-test/build.gradle.kts
@@ -60,8 +60,8 @@ tasks.withType<KotlinCompile> {
             "kotlin-stdlib",
             "-Xallow-kotlin-package",
             "-Xmulti-platform",
-            "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
-            "-Xuse-experimental=kotlin.Experimental"
+            "-Xopt-in=kotlin.RequiresOptIn",
+            "-Xopt-in=kotlin.contracts.ExperimentalContracts"
         )
     }
 }
diff --git a/libraries/stdlib/jvm/build.gradle b/libraries/stdlib/jvm/build.gradle
index 0c396f475f1..976e4092183 100644
--- a/libraries/stdlib/jvm/build.gradle
+++ b/libraries/stdlib/jvm/build.gradle
@@ -120,9 +120,9 @@ compileKotlin {
                 "-Xmultifile-parts-inherit",
                 "-Xnormalize-constructor-calls=enable",
                 "-module-name", "kotlin-stdlib",
-                "-Xuse-experimental=kotlin.Experimental",
-                "-Xuse-experimental=kotlin.ExperimentalMultiplatform",
-                "-Xuse-experimental=kotlin.contracts.ExperimentalContracts",
+                "-Xopt-in=kotlin.RequiresOptIn",
+                "-Xopt-in=kotlin.ExperimentalMultiplatform",
+                "-Xopt-in=kotlin.contracts.ExperimentalContracts",
                 "-Xinline-classes"
         ]
     }
@@ -134,15 +134,15 @@ compileJava9Sources(project, 'kotlin.stdlib', [sourceSets.main.output])
 compileTestKotlin {
     kotlinOptions {
         freeCompilerArgs += [
-                "-Xuse-experimental=kotlin.Experimental",
-                "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-                "-Xuse-experimental=kotlin.ExperimentalStdlibApi"
+                "-Xopt-in=kotlin.RequiresOptIn",
+                "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
+                "-Xopt-in=kotlin.ExperimentalStdlibApi",
         ]
     }
 }
 
 compileLongRunningTestKotlin {
-    kotlinOptions.freeCompilerArgs += "-Xuse-experimental=kotlin.ExperimentalStdlibApi"
+    kotlinOptions.freeCompilerArgs += "-Xopt-in=kotlin.ExperimentalStdlibApi"
 }
 
 task longRunningTest(type: Test, dependsOn: longRunningTestClasses) {
diff --git a/libraries/stdlib/samples/build.gradle b/libraries/stdlib/samples/build.gradle
index 0ce806d3947..050c8601400 100644
--- a/libraries/stdlib/samples/build.gradle
+++ b/libraries/stdlib/samples/build.gradle
@@ -13,9 +13,9 @@ compileTestKotlin {
     kotlinOptions {
         jdkHome = JDK_18
         freeCompilerArgs = [
-                "-Xuse-experimental=kotlin.ExperimentalStdlibApi",
-                "-Xuse-experimental=kotlin.ExperimentalUnsignedTypes",
-                "-Xuse-experimental=kotlin.time.ExperimentalTime"
+                "-Xopt-in=kotlin.ExperimentalStdlibApi",
+                "-Xopt-in=kotlin.ExperimentalUnsignedTypes",
+                "-Xopt-in=kotlin.time.ExperimentalTime",
         ]
     }
 }
diff --git a/libraries/tools/kotlinp/build.gradle.kts b/libraries/tools/kotlinp/build.gradle.kts
index 495ff9a42b1..27a5c314945 100644
--- a/libraries/tools/kotlinp/build.gradle.kts
+++ b/libraries/tools/kotlinp/build.gradle.kts
@@ -70,6 +70,6 @@ tasks {
 
 tasks.withType<KotlinCompile> {
     kotlinOptions {
-        freeCompilerArgs += listOf("-Xuse-experimental=kotlin.Experimental")
+        freeCompilerArgs += listOf("-Xopt-in=kotlin.RequiresOptIn")
     }
 }
\ No newline at end of file