diff --git a/libraries/tools/kotlin-gradle-plugin/api/kotlin-gradle-plugin.api b/libraries/tools/kotlin-gradle-plugin/api/kotlin-gradle-plugin.api
index a7a07d963de..bfa58ed241a 100644
--- a/libraries/tools/kotlin-gradle-plugin/api/kotlin-gradle-plugin.api
+++ b/libraries/tools/kotlin-gradle-plugin/api/kotlin-gradle-plugin.api
@@ -747,9 +747,14 @@ public abstract interface class org/jetbrains/kotlin/gradle/plugin/mpp/external/
 }
 
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor$CompilationAssociator {
+	public static final field Companion Lorg/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor$CompilationAssociator$Companion;
 	public abstract fun associate (Lorg/jetbrains/kotlin/gradle/plugin/mpp/external/DecoratedExternalKotlinCompilation;Lorg/jetbrains/kotlin/gradle/plugin/mpp/external/DecoratedExternalKotlinCompilation;)V
 }
 
+public final class org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor$CompilationAssociator$Companion {
+	public final fun getDefault ()Lorg/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor$CompilationAssociator;
+}
+
 public abstract interface class org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor$CompilationFactory {
 	public abstract fun create (Lorg/jetbrains/kotlin/gradle/plugin/mpp/external/DecoratedExternalKotlinCompilation$Delegate;)Lorg/jetbrains/kotlin/gradle/plugin/mpp/DecoratedKotlinCompilation;
 }
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor.kt
index a0dbfd607b0..50dec688901 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/ExternalKotlinCompilationDescriptor.kt
@@ -12,7 +12,9 @@ import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSet
 import org.jetbrains.kotlin.gradle.plugin.KotlinTarget
 import org.jetbrains.kotlin.gradle.plugin.hierarchy.KotlinSourceSetTreeClassifier
 import org.jetbrains.kotlin.gradle.plugin.mpp.DecoratedKotlinCompilation
+import org.jetbrains.kotlin.gradle.plugin.mpp.compilationImpl.DefaultKotlinCompilationAssociator
 import org.jetbrains.kotlin.gradle.plugin.mpp.external.ExternalKotlinCompilationDescriptor.*
+import org.jetbrains.kotlin.gradle.plugin.mpp.internal
 import org.jetbrains.kotlin.gradle.plugin.mpp.targetHierarchy.SourceSetTreeClassifier
 import kotlin.properties.Delegates
 
@@ -45,8 +47,15 @@ interface ExternalKotlinCompilationDescriptor<T : DecoratedExternalKotlinCompila
      * handling them on behalf of the authors of the external [KotlinTarget]
      */
     @ExternalKotlinTargetApi
-    fun interface CompilationAssociator<T : DecoratedExternalKotlinCompilation> {
+    fun interface CompilationAssociator<in T : DecoratedExternalKotlinCompilation> {
         fun associate(auxiliary: T, main: DecoratedExternalKotlinCompilation)
+
+        @ExternalKotlinTargetApi
+        companion object {
+            val default = CompilationAssociator<DecoratedExternalKotlinCompilation> { aux, main ->
+                DefaultKotlinCompilationAssociator.associate(aux.target, aux.compilation.internal, main.compilation.internal)
+            }
+        }
     }
 
     val compilationName: String
@@ -55,7 +64,7 @@ interface ExternalKotlinCompilationDescriptor<T : DecoratedExternalKotlinCompila
     val defaultSourceSet: KotlinSourceSet
     val compilationFactory: CompilationFactory<T>
     val friendArtifactResolver: FriendArtifactResolver<T>?
-    val compilationAssociator: CompilationAssociator<T>?
+    val compilationAssociator: CompilationAssociator<T>
 
     @Suppress("DEPRECATION")
     @Deprecated("Use .sourceSetTreeClassifierV2 instead")
@@ -93,7 +102,7 @@ class ExternalKotlinCompilationDescriptorBuilder<T : DecoratedExternalKotlinComp
     var defaultSourceSet: KotlinSourceSet by Delegates.notNull()
     var compilationFactory: CompilationFactory<T> by Delegates.notNull()
     var friendArtifactResolver: FriendArtifactResolver<T>? = null
-    var compilationAssociator: CompilationAssociator<T>? = null
+    var compilationAssociator: CompilationAssociator<T> = CompilationAssociator.default
 
     @Suppress("DEPRECATION")
     @Deprecated("Use sourceSetTreeClassifierV2 instead")
@@ -117,7 +126,7 @@ private data class ExternalKotlinCompilationDescriptorImpl<T : DecoratedExternal
     override val defaultSourceSet: KotlinSourceSet,
     override val compilationFactory: CompilationFactory<T>,
     override val friendArtifactResolver: FriendArtifactResolver<T>?,
-    override val compilationAssociator: CompilationAssociator<T>?,
+    override val compilationAssociator: CompilationAssociator<T>,
     @Deprecated("Use .sourceSetTreeClassifierV2 instead")
     @Suppress("DEPRECATION")
     override val sourceSetTreeClassifier: SourceSetTreeClassifier,
diff --git a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/createExternalKotlinCompilation.kt b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/createExternalKotlinCompilation.kt
index af1771381c3..058ad88d970 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/createExternalKotlinCompilation.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/common/kotlin/org/jetbrains/kotlin/gradle/plugin/mpp/external/createExternalKotlinCompilation.kt
@@ -9,7 +9,6 @@ import org.jetbrains.kotlin.gradle.ExternalKotlinTargetApi
 import org.jetbrains.kotlin.gradle.plugin.*
 import org.jetbrains.kotlin.gradle.plugin.hierarchy.SourceSetTreeClassifierWrapper
 import org.jetbrains.kotlin.gradle.plugin.hierarchy.sourceSetTreeClassifier
-import org.jetbrains.kotlin.gradle.plugin.mpp.compilationImpl.DefaultKotlinCompilationAssociator
 import org.jetbrains.kotlin.gradle.plugin.mpp.compilationImpl.DefaultKotlinCompilationFriendPathsResolver
 import org.jetbrains.kotlin.gradle.plugin.mpp.compilationImpl.KotlinCompilationAssociator
 import org.jetbrains.kotlin.gradle.plugin.mpp.compilationImpl.KotlinCompilationSourceSetsContainer
@@ -50,12 +49,12 @@ fun <T : DecoratedExternalKotlinCompilation> DecoratedExternalKotlinTarget.creat
                 compileAllTaskName = descriptor.compileAllTaskName ?: default.compileAllTaskName
             )
         },
-        compilationAssociator = descriptor.compilationAssociator?.let { declaredAssociator ->
-            @Suppress("unchecked_cast")
-            KotlinCompilationAssociator { _, first, second ->
-                declaredAssociator.associate(first.decoratedInstance as T, second.decoratedInstance as DecoratedExternalKotlinCompilation)
-            }
-        } ?: DefaultKotlinCompilationAssociator,
+        compilationAssociator = @Suppress("unchecked_cast") KotlinCompilationAssociator { _, first, second ->
+            descriptor.compilationAssociator.associate(
+                first.decoratedInstance as T,
+                second.decoratedInstance as DecoratedExternalKotlinCompilation
+            )
+        },
         compilationFriendPathsResolver = DefaultKotlinCompilationFriendPathsResolver(
             DefaultKotlinCompilationFriendPathsResolver.FriendArtifactResolver.composite(
                 DefaultKotlinCompilationFriendPathsResolver.DefaultFriendArtifactResolver,
diff --git a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/unitTests/ExternalKotlinTargetApiTests.kt b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/unitTests/ExternalKotlinTargetApiTests.kt
index 76ca1902d81..28feeeb2f2b 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/unitTests/ExternalKotlinTargetApiTests.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/functionalTest/kotlin/org/jetbrains/kotlin/gradle/unitTests/ExternalKotlinTargetApiTests.kt
@@ -17,12 +17,15 @@ import org.jetbrains.kotlin.gradle.plugin.KotlinSourceSetTree
 import org.jetbrains.kotlin.gradle.plugin.hierarchy.KotlinSourceSetTreeClassifier
 import org.jetbrains.kotlin.gradle.plugin.hierarchy.orNull
 import org.jetbrains.kotlin.gradle.plugin.launchInStage
+import org.jetbrains.kotlin.gradle.plugin.mpp.external.ExternalKotlinCompilationDescriptor.CompilationAssociator
 import org.jetbrains.kotlin.gradle.plugin.mpp.external.ExternalKotlinCompilationDescriptor.CompilationFactory
+import org.jetbrains.kotlin.gradle.plugin.mpp.external.ExternalKotlinCompilationDescriptorBuilder
 import org.jetbrains.kotlin.gradle.plugin.mpp.external.createCompilation
 import org.jetbrains.kotlin.gradle.plugin.mpp.external.createExternalKotlinTarget
 import org.jetbrains.kotlin.gradle.util.*
 import org.jetbrains.kotlin.gradle.utils.property
 import org.jetbrains.kotlin.gradle.utils.toMap
+import org.jetbrains.kotlin.tooling.core.extrasKeyOf
 import kotlin.test.*
 
 class ExternalKotlinTargetApiTests {
@@ -77,6 +80,57 @@ class ExternalKotlinTargetApiTests {
         assertNull(KotlinSourceSetTree.orNull(auxCompilation))
     }
 
+    @Test
+    fun `test - compilation associator - default`() {
+        val target = kotlin.createExternalKotlinTarget<FakeTarget> { defaults() }
+
+        val mainCompilation = target.createCompilation<FakeCompilation> {
+            assertEquals(
+                CompilationAssociator.default, compilationAssociator,
+                "Expected CompilationAssociator.default being set in ${ExternalKotlinCompilationDescriptorBuilder::class.simpleName}"
+            )
+
+            defaults(kotlin)
+            compileTaskName = "main"
+        }
+
+        val auxCompilation = target.createCompilation<FakeCompilation> {
+            defaults(kotlin)
+            compilationName = "aux"
+        }
+
+        auxCompilation.associateWith(mainCompilation)
+        assertEquals(setOf(mainCompilation), auxCompilation.associateWith.toSet())
+    }
+
+    @Test
+    fun `test - compilation associator - custom`() {
+        val target = kotlin.createExternalKotlinTarget<FakeTarget> { defaults() }
+        val testTraceKey = extrasKeyOf<String>("testTrace")
+
+        val compilationAssociator = CompilationAssociator<FakeCompilation> { auxiliary, main ->
+            auxiliary.extras[testTraceKey] = "aux"
+            main.extras[testTraceKey] = "main"
+        }
+
+        val mainCompilation = target.createCompilation<FakeCompilation> {
+            defaults(kotlin)
+            this.compilationAssociator = compilationAssociator
+            this.compileTaskName = "main"
+        }
+
+        val auxCompilation = target.createCompilation<FakeCompilation> {
+            defaults(kotlin)
+            this.compilationName = "aux"
+            this.compilationAssociator = compilationAssociator
+        }
+
+        auxCompilation.associateWith(mainCompilation)
+
+        assertEquals("aux", auxCompilation.extras[testTraceKey])
+        assertEquals("main", mainCompilation.extras[testTraceKey])
+    }
+
     @Test
     fun `test - sourcesElements - default configuration`() = buildProjectWithMPP().runLifecycleAwareTest {
         val target = kotlin.createExternalKotlinTarget<FakeTarget> { defaults() }