diff --git a/clang/lib/Sema/TreeTransform.h b/clang/lib/Sema/TreeTransform.h
--- a/clang/lib/Sema/TreeTransform.h
+++ b/clang/lib/Sema/TreeTransform.h
@@ -11882,7 +11882,7 @@
           Sema::ExpressionEvaluationContext::PotentiallyEvaluatedIfUsed, P);
       ExprResult R = getDerived().TransformExpr(
           E->getCallOperator()->getParamDecl(I)->getDefaultArg());
-      P->setDefaultArg(R.get());
+      getSema().SetParamDefaultArgument(P, R.get(), R.get()->getBeginLoc());
     }
   }