diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/tasks/KotlinPackageJsonTask.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/tasks/KotlinPackageJsonTask.kt
index c67ee0474bb..2946f97cc20 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/tasks/KotlinPackageJsonTask.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/npm/tasks/KotlinPackageJsonTask.kt
@@ -62,7 +62,7 @@ open class KotlinPackageJsonTask : DefaultTask() {
         producer.internalDependencies.map { dependency ->
             npmResolutionManager.resolver[dependency.projectPath][dependency.compilationName].npmProject.packageJsonTaskPath
         } + producer.internalCompositeDependencies.map { dependency ->
-            dependency.includedBuild?.task(":$PACKAGE_JSON_UMBRELLA_TASK_NAME") ?: "includedBuild instance is not available"
+            dependency.includedBuild?.task(":$PACKAGE_JSON_UMBRELLA_TASK_NAME") ?: error("includedBuild instance is not available")
         }
 
     @get:Input