1 files changed, 7 insertions, 2 deletions
diff --git a/clang/lib/Sema/SemaCXXScopeSpec.cpp b/clang/lib/Sema/SemaCXXScopeSpec.cpp
index a70aca2ad86..b1b8b5d1dc9 100644
--- a/clang/lib/Sema/SemaCXXScopeSpec.cpp
+++ b/clang/lib/Sema/SemaCXXScopeSpec.cpp
@@ -703,8 +703,13 @@ bool Sema::BuildCXXNestedNameSpecifier(Scope *S,
   if (getLangOpts().MSVCCompat) {
     DeclContext *DC = LookupCtx ? LookupCtx : CurContext;
     if (DC->isDependentContext() && DC->isFunctionOrMethod()) {
-      SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
-      return false;
+      CXXRecordDecl *ContainingClass = dyn_cast<CXXRecordDecl>(DC->getParent());
+      if (ContainingClass && ContainingClass->hasAnyDependentBases()) {
+        Diag(IdentifierLoc, diag::ext_undeclared_unqual_id_with_dependent_base)
+            << &Identifier << ContainingClass;
+        SS.Extend(Context, &Identifier, IdentifierLoc, CCLoc);
+        return false;
+      }
     }
   }