diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 5fd38f71ed20..7995def33224 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -39,6 +39,8 @@ namespace {
     // FIXME: Once we get closer to completion, replace these
     // manually-written declarations with automatically-generated ones
     // from clang/AST/DeclNodes.def.
+    Decl *VisitTranslationUnitDecl(TranslationUnitDecl *D);
+    Decl *VisitNamespaceDecl(NamespaceDecl *D);
     Decl *VisitTypedefDecl(TypedefDecl *D);
     Decl *VisitFieldDecl(FieldDecl *D);
     Decl *VisitStaticAssertDecl(StaticAssertDecl *D);
@@ -63,6 +65,18 @@ namespace {
   };
 }
 
+Decl *
+TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
+  assert(false && "Translation units cannot be instantiated");
+  return D;
+}
+
+Decl *
+TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
+  assert(false && "Namespaces cannot be instantiated");
+  return D;
+}
+
 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
   bool Invalid = false;
   QualType T = D->getUnderlyingType();