diff --git a/clang/lib/Sema/SemaOpenMP.cpp b/clang/lib/Sema/SemaOpenMP.cpp
index 64e7b9d..5d253cd 100644
--- a/clang/lib/Sema/SemaOpenMP.cpp
+++ b/clang/lib/Sema/SemaOpenMP.cpp
@@ -11979,7 +11979,7 @@
     else if (I + Skipped + 1 != Last)
       Out << ", ";
   }
-  return Out.str();
+  return std::string(Out.str());
 }
 
 OMPClause *Sema::ActOnOpenMPDefaultClause(OpenMPDefaultClauseKind Kind,