diff --git lib/AST/MicrosoftMangle.cpp lib/AST/MicrosoftMangle.cpp
index e2cee7f..381fc26 100644
--- lib/AST/MicrosoftMangle.cpp
+++ lib/AST/MicrosoftMangle.cpp
@@ -1059,6 +1059,8 @@ void MicrosoftCXXNameMangler::mangleType(const FunctionProtoType *T,
                                          SourceRange) {
   // Structors only appear in decls, so at this point we know it's not a
   // structor type.
+  // FIXME: This may not be block- or lambda-friendly.
+  Out << "$$A6";
   mangleType(T, NULL, false, false);
 }
 void MicrosoftCXXNameMangler::mangleType(const FunctionNoProtoType *T,
diff --git test/CodeGenCXX/mangle-ms-template-callback.cpp test/CodeGenCXX/mangle-ms-template-callback.cpp
new file mode 100644
index 0000000..b000348
--- /dev/null
+++ test/CodeGenCXX/mangle-ms-template-callback.cpp
@@ -0,0 +1,76 @@
+// RUN: %clang_cc1 -fblocks -emit-llvm %s -o - -cxx-abi microsoft -triple=i386-pc-win32 | FileCheck %s
+
+template<typename Signature>
+class C;
+
+template<typename Ret>
+class C<Ret(void)> {};
+typedef C<void(void)> C0;
+
+template<typename Ret, typename Arg1>
+class C<Ret(Arg1)> {};
+
+template<typename Ret, typename Arg1, typename Arg2>
+class C<Ret(Arg1, Arg2)> {};
+
+C0 callback_void;
+// CHECK: "\01?callback_void@@3V?$C@$$A6AXXZ@@A"
+
+volatile C0 callback_void_volatile;
+// CHECK: "\01?callback_void_volatile@@3V?$C@$$A6AXXZ@@C"
+
+class Type {};
+
+C<int(void)> callback_int;
+// CHECK: "\01?callback_int@@3V?$C@$$A6AHXZ@@A"
+C<Type(void)> callback_Type;
+// CHECK: "\01?callback_Type@@3V?$C@$$A6A?AVType@@XZ@@A"
+
+C<void(int)> callback_void_int;
+// CHECK: "\01?callback_void_int@@3V?$C@$$A6AXH@Z@@A"
+C<int(int)> callback_int_int;
+// CHECK: "\01?callback_int_int@@3V?$C@$$A6AHH@Z@@A"
+C<void(Type)> callback_void_Type;
+// CHECK: "\01?callback_void_Type@@3V?$C@$$A6AXVType@@@Z@@A"
+
+void foo(C0 c) {}
+// CHECK: "\01?foo@@YAXV?$C@$$A6AXXZ@@@Z"
+
+// Here be dragons!
+// Let's face the magic of template partial specialization...
+
+void function(C<void(void)>) {}
+// CHECK: "\01?function@@YAXV?$C@$$A6AXXZ@@@Z"
+
+template<typename Ret> class C<Ret(*)(void)> {};
+void function_pointer(C<void(*)(void)>) {}
+// CHECK: "\01?function_pointer@@YAXV?$C@P6AXXZ@@@Z"
+
+// Block equivalent to the previous definitions.
+template<typename Ret> class C<Ret(^)(void)> {};
+void block(C<void(^)(void)>) {}
+// CHECK: "\01?block@@YAXV?$C@P_E$$A6AXXZ@@@Z"
+// FIXME we might want to mangle like this instead:
+//        "\01?block@@YAXV?$C@P_E6AXXZ@@@Z"
+// FYI blocks are not present in MSVS, so we're free to choose the spec.
+
+template<typename T> class C<void (T::*)(void)> {};
+class Z {
+ public:
+  void method() {}
+};
+void member_pointer(C<void (Z::*)(void)>) {}
+// CHECK: "\01?member_pointer@@YAXV?$C@P8Z@@AEXXZ@@@Z"
+
+template<typename T> void bar(T) {}
+
+void call_bar() {
+  bar<int (*)(int)>(0);
+// CHECK: "\01??$bar@P6AHH@Z@@YAXP6AHH@Z@Z"
+
+  bar<int (^)(int)>(0);
+// CHECK: "\01??$bar@P_E$$A6AHH@Z@@YAXP_E$$A6AHH@Z@Z"
+// FIXME we might want to mangle like this instead:
+//        "\01??$bar@P_E6AHH@Z@@YAXP_E6AHH@Z@Z"
+// FYI blocks are not present in MSVS, so we're free to choose the spec.
+}
diff --git test/CodeGenCXX/mangle-ms.cpp test/CodeGenCXX/mangle-ms.cpp
index f392c17..54833fc 100644
--- test/CodeGenCXX/mangle-ms.cpp
+++ test/CodeGenCXX/mangle-ms.cpp
@@ -126,7 +126,10 @@ void zeta(int (*)(int, int)) {}
 // Blocks mangling (Clang extension). A block should be mangled slightly
 // differently from a similar function pointer.
 void eta(int (^)(int, int)) {}
-// CHECK: @"\01?eta@@YAXP_EAHHH@Z@Z"
+// CHECK: @"\01?eta@@YAXP_E$$A6AHHH@Z@Z"
+// FIXME we might want to mangle like this instead:
+//        @"\01?eta@@YAXP_EAHHH@Z@Z"
+// FYI blocks are not present in MSVS, so we're free to choose the spec.
 
 void operator_new_delete() {
   char *ptr = new char;