Index: cfe/trunk/lib/AST/ItaniumMangle.cpp
===================================================================
--- cfe/trunk/lib/AST/ItaniumMangle.cpp
+++ cfe/trunk/lib/AST/ItaniumMangle.cpp
@@ -1455,10 +1455,12 @@
   Out << 'N';
   if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(ND)) {
     Qualifiers MethodQuals =
-        Qualifiers::fromCVRMask(Method->getTypeQualifiers());
+        Qualifiers::fromCVRUMask(Method->getTypeQualifiers());
     // We do not consider restrict a distinguishing attribute for overloading
     // purposes so we must not mangle it.
     MethodQuals.removeRestrict();
+    // __unaligned is not currently mangled in any way, so remove it.
+    MethodQuals.removeUnaligned();
     mangleQualifiers(MethodQuals);
     mangleRefQualifier(Method->getRefQualifier());
   }
Index: cfe/trunk/test/CodeGenCXX/unaligned-duplicated-mangle-name.cpp
===================================================================
--- cfe/trunk/test/CodeGenCXX/unaligned-duplicated-mangle-name.cpp
+++ cfe/trunk/test/CodeGenCXX/unaligned-duplicated-mangle-name.cpp
@@ -0,0 +1,20 @@
+// RUN: %clang_cc1 -triple %itanium_abi_triple -fms-extensions -emit-llvm-only %s -verify
+
+struct A
+{
+    int x;
+    void foo() __unaligned;
+    void foo();
+};
+
+void A::foo() __unaligned
+{
+    this->x++;
+}
+
+void A::foo() // expected-error {{definition with same mangled name as another definition}}
+              // expected-note@-6 {{previous definition is here}}
+{
+    this->x++;
+}
+