diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinProperties.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinProperties.kt
index bddbe1ba6cb..21ba3dd7a40 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinProperties.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/plugin/KotlinProperties.kt
@@ -174,7 +174,7 @@ internal class PropertiesProvider private constructor(private val project: Proje
      * Use Kotlin/JS backend mode
      */
     val jsCompiler: JsCompilerType
-        get() = property(jsCompilerProperty)?.let { JsCompilerType.byArgument(it) } ?: JsCompilerType.ir
+        get() = property(jsCompilerProperty)?.let { JsCompilerType.byArgument(it) } ?: JsCompilerType.legacy
 
     private fun propertyWithDeprecatedVariant(propName: String, deprecatedPropName: String): String? {
         val deprecatedProperty = property(deprecatedPropName)