diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index ab61487b68b3..a2d0e1872856 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -3098,6 +3098,9 @@ Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
         assert(Param->getDeclContext() != NewFD && "Was set before ?");
         Param->setDeclContext(NewFD);
         Params.push_back(Param);
+
+        if (Param->isInvalidDecl())
+          NewFD->setInvalidDecl();
       }
     }
 
diff --git a/clang/test/SemaTemplate/instantiate-method.cpp b/clang/test/SemaTemplate/instantiate-method.cpp
index 635d839b2bd2..3ef07d356d3e 100644
--- a/clang/test/SemaTemplate/instantiate-method.cpp
+++ b/clang/test/SemaTemplate/instantiate-method.cpp
@@ -117,3 +117,13 @@ struct X3 {
 
 
 template struct X3<double>;
+
+// Don't try to instantiate this, it's invalid.
+namespace test1 {
+  template <class T> class A {};
+  template <class T> class B {
+    void foo(A<test1::Undeclared> &a) // expected-error {{no member named 'Undeclared' in namespace 'test1'}}
+    {}
+  };
+  template class B<int>;
+}