diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index f58125d..300e7c4 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -1685,7 +1685,7 @@
                                              IdentifierInfo *Ident) {
   
   // Check if we have a previous declaration with the same name.
-  if (NamedDecl *PrevDecl = LookupName(S, Alias, LookupOrdinaryName)) {
+  if (NamedDecl *PrevDecl = LookupName(S, Alias, LookupOrdinaryName, true)) {
     // FIXME: If this is a namespace alias decl, and it points to the same 
     // namespace, we shouldn't warn.
     unsigned DiagID = isa<NamespaceDecl>(PrevDecl) ? diag::err_redefinition :
diff --git a/test/SemaCXX/namespace-alias.cpp b/test/SemaCXX/namespace-alias.cpp
index b05db5f..87e8b2c 100644
--- a/test/SemaCXX/namespace-alias.cpp
+++ b/test/SemaCXX/namespace-alias.cpp
@@ -21,3 +21,7 @@
   using namespace A;
   namespace D = B; // expected-error {{reference to 'B' is ambiguous}}
 }
+
+namespace G { 
+  namespace B = N;
+}