diff --git a/native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/approximationKeys.kt b/native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/approximationKeys.kt
index 7ee16aa11d7..4577b8e37cc 100644
--- a/native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/approximationKeys.kt
+++ b/native/commonizer/src/org/jetbrains/kotlin/commonizer/mergedtree/approximationKeys.kt
@@ -164,8 +164,8 @@ private fun StringBuilder.appendTypeParameterTypeApproximationSignature(
             appendTypeApproximationSignature(context, upperBound)
             if (index != typeParameter.upperBounds.lastIndex) append(", ")
         }
+        append("]")
     }
-    append("]")
     if (type.isMarkedNullable) append("?")
 }