diff --git a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/JvmSimpleNameBacktickChecker.kt b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/JvmSimpleNameBacktickChecker.kt
index e1c26e0d41d..e8c5969f883 100644
--- a/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/JvmSimpleNameBacktickChecker.kt
+++ b/compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/JvmSimpleNameBacktickChecker.kt
@@ -24,7 +24,7 @@ import org.jetbrains.kotlin.resolve.IdentifierChecker
 
 object JvmSimpleNameBacktickChecker : IdentifierChecker {
     // See The Java Virtual Machine Specification, section 4.7.9.1 https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.9.1
-    private val CHARS = setOf('.', ';', '[', ']', '/', '<', '>', ':', '\\')
+    val INVALID_CHARS = setOf('.', ';', '[', ']', '/', '<', '>', ':', '\\')
 
     override fun checkIdentifier(simpleNameExpression: KtSimpleNameExpression, diagnosticHolder: DiagnosticSink) {
         reportIfNeeded(simpleNameExpression.getReferencedName(), { simpleNameExpression.getIdentifier() }, diagnosticHolder)
@@ -55,16 +55,13 @@ object JvmSimpleNameBacktickChecker : IdentifierChecker {
         val text = KtPsiUtil.unquoteIdentifier(name)
         if (text.isEmpty()) {
             diagnosticHolder.report(Errors.INVALID_CHARACTERS.on(reportOn() ?: return, "should not be empty"))
-        } else if (text.any { it in CHARS }) {
+        } else if (text.any { it in INVALID_CHARS }) {
             diagnosticHolder.report(
                 Errors.INVALID_CHARACTERS.on(
                     reportOn() ?: return,
-                    "contains illegal characters: ${CHARS.intersect(text.toSet()).joinToString(
-                        ""
-                    )}"
+                    "contains illegal characters: ${INVALID_CHARS.intersect(text.toSet()).joinToString("")}"
                 )
             )
         }
     }
 }
-
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt
index c4d8e6dade6..21d264875fb 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt
@@ -39,6 +39,7 @@ import org.jetbrains.kotlin.resolve.jvm.AsmTypes
 import org.jetbrains.kotlin.resolve.jvm.annotations.JVM_SYNTHETIC_ANNOTATION_FQ_NAME
 import org.jetbrains.kotlin.resolve.jvm.annotations.TRANSIENT_ANNOTATION_FQ_NAME
 import org.jetbrains.kotlin.resolve.jvm.annotations.VOLATILE_ANNOTATION_FQ_NAME
+import org.jetbrains.kotlin.resolve.jvm.checkers.JvmSimpleNameBacktickChecker
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.JvmDeclarationOrigin
 import org.jetbrains.kotlin.resolve.jvm.diagnostics.OtherOrigin
 import org.jetbrains.kotlin.resolve.jvm.jvmSignature.JvmClassSignature
@@ -111,8 +112,6 @@ open class ClassCodegen protected constructor(
         val signature = getSignature(irClass, type, superClassInfo, typeMapper)
 
         // Ensure that the backend only produces class names that would be valid in the frontend for JVM.
-        // hasInvalidName() uses a set copied from JvmSimpleNameBacktickChecker, which in turn references JVMS 4.7.9.1:
-        // https://docs.oracle.com/javase/specs/jvms/se8/html/jvms-4.html#jvms-4.7.9.1.
         if (context.state.classBuilderMode.generateBodies && signature.hasInvalidName()) {
             throw IllegalStateException("Generating class with invalid name '${type.className}': ${irClass.dump()}")
         }
@@ -291,11 +290,8 @@ open class ClassCodegen protected constructor(
             ClassCodegen(irClass, context).generate()
         }
 
-        // Note: This is copied from JvmSimpleNameBacktickChecker.
-        private val INVALID_CHARS = setOf('.', ';', '[', ']', '/', '<', '>', ':', '\\')
-
         private fun JvmClassSignature.hasInvalidName() =
-            name.splitToSequence('/').any { identifier -> identifier.any { it in INVALID_CHARS } }
+            name.splitToSequence('/').any { identifier -> identifier.any { it in JvmSimpleNameBacktickChecker.INVALID_CHARS } }
     }
 
     private fun generateDeclaration(declaration: IrDeclaration) {