diff --git a/include/msctf.idl b/include/msctf.idl
index a3db32e13e6..e4b54e4c67e 100644
--- a/include/msctf.idl
+++ b/include/msctf.idl
@@ -84,6 +84,8 @@ cpp_quote("#define TF_MOD_IGNORE_ALL_MODIFIER   0x0400")
 cpp_quote("#define TF_PROFILETYPE_INPUTPROCESSOR  0x0001")
 cpp_quote("#define TF_PROFILETYPE_KEYBOARDLAYOUT  0x0002")
 
+cpp_quote("#define TF_IPSINK_FLAG_ACTIVE 0x0001")
+
 interface ITfDocumentMgr;
 interface ITfContext;
 interface IEnumTfDocumentMgrs;
@@ -326,6 +328,8 @@ interface ITfContext : IUnknown
 
 };
 
+const DWORD TF_INVALID_COOKIE = 0xffffffff;
+
 [
   object,
   uuid(4ea48a35-60ae-446f-8fd6-e6a8d82459f7),
@@ -1522,3 +1526,20 @@ interface ITfThreadFocusSink : IUnknown
 
     HRESULT OnKillThreadFocus();
 };
+
+[
+  object,
+  uuid(71c6e74e-0f28-11d8-a82a-00065b84435c),
+  pointer_default(unique)
+]
+interface ITfInputProcessorProfileActivationSink : IUnknown
+{
+    HRESULT OnActivated(
+        [in] DWORD dwProfileType,
+        [in] LANGID langid,
+        [in] REFCLSID clsid,
+        [in] REFGUID catid,
+        [in] REFGUID guidProfile,
+        [in] HKL hkl,
+        [in] DWORD dwFlags);
+}