diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index 1892809..4fe5576 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -1540,6 +1540,7 @@
     LinkageSpecDecl *CLinkageDecl =
         LinkageSpecDecl::Create(Context, Parent, Loc, Loc,
                                 LinkageSpecDecl::lang_c, false);
+    CLinkageDecl->setImplicit();
     Parent->addDecl(CLinkageDecl);
     Parent = CLinkageDecl;
   }