diff --git a/compiler/fir/tree/build.gradle.kts b/compiler/fir/tree/build.gradle.kts
index 8a6b4d3d1e1..f2a608fb727 100644
--- a/compiler/fir/tree/build.gradle.kts
+++ b/compiler/fir/tree/build.gradle.kts
@@ -56,3 +56,9 @@ if (kotlinBuildProperties.isInJpsBuildIdeaSync) {
         this.module.generatedSourceDirs.add(generationRoot)
     }
 }
+
+kotlin {
+    sourceSets.all {
+        languageSettings.enableLanguageFeature("InlineClasses")
+    }
+}
\ No newline at end of file