diff --git a/plugins/kapt3/kapt3-idea/src/org/jetbrains/kotlin/kapt/idea/KaptProjectResolverExtension.kt b/plugins/kapt3/kapt3-idea/src/org/jetbrains/kotlin/kapt/idea/KaptProjectResolverExtension.kt
index 956d5a58a6b..7f326a41dc1 100644
--- a/plugins/kapt3/kapt3-idea/src/org/jetbrains/kotlin/kapt/idea/KaptProjectResolverExtension.kt
+++ b/plugins/kapt3/kapt3-idea/src/org/jetbrains/kotlin/kapt/idea/KaptProjectResolverExtension.kt
@@ -72,7 +72,7 @@ class KaptProjectResolverExtension : AbstractProjectResolverExtension() {
     }
 
     override fun getExtraProjectModelClasses() = setOf(KaptGradleModel::class.java)
-    override fun getToolingExtensionsClasses() = setOf(KaptModelBuilderService::class.java)
+    override fun getToolingExtensionsClasses() = setOf(KaptModelBuilderService::class.java, Unit::class.java)
 
     override fun populateModuleExtraModels(gradleModule: IdeaModule, ideModule: DataNode<ModuleData>) {
         val kaptModel = resolverCtx.getExtraProject(gradleModule, KaptGradleModel::class.java) ?: return