diff --git a/dlls/rpcrt4/rpcrt4.spec b/dlls/rpcrt4/rpcrt4.spec
index a235302ecb5..da54ddff5d8 100644
--- a/dlls/rpcrt4/rpcrt4.spec
+++ b/dlls/rpcrt4/rpcrt4.spec
@@ -363,7 +363,7 @@
 @ stdcall RpcBindingVectorFree(ptr)
 @ stdcall RpcCancelAsyncCall(ptr long) RpcAsyncCancelCall
 @ stdcall RpcCancelThread(ptr)
-@ stub RpcCancelThreadEx
+@ stdcall RpcCancelThreadEx(ptr long)
 @ stub RpcCertGeneratePrincipalNameA
 @ stub RpcCertGeneratePrincipalNameW
 @ stdcall RpcCompleteAsyncCall(ptr ptr) RpcAsyncCompleteCall
diff --git a/dlls/rpcrt4/rpcrt4_main.c b/dlls/rpcrt4/rpcrt4_main.c
index 6ff93f2ba03..4438f52e4ab 100644
--- a/dlls/rpcrt4/rpcrt4_main.c
+++ b/dlls/rpcrt4/rpcrt4_main.c
@@ -1081,3 +1081,12 @@ RPC_STATUS RPC_ENTRY RpcCancelThread(void* ThreadHandle)
 
     return RPC_S_OK;
 }
+
+/******************************************************************************
+ * RpcCancelThreadEx   (rpcrt4.@)
+ */
+RPC_STATUS RPC_ENTRY RpcCancelThreadEx(void* ThreadHandle, LONG Timeout)
+{
+    FIXME("(%p, %d)\n", ThreadHandle, Timeout);
+    return RPC_S_OK;
+}
diff --git a/include/rpcdce.h b/include/rpcdce.h
index 1b8b6e71376..79716ae9d6f 100644
--- a/include/rpcdce.h
+++ b/include/rpcdce.h
@@ -469,6 +469,7 @@ RPCRTAPI RPC_STATUS RPC_ENTRY
 #define RpcBindingInqAuthInfo WINELIB_NAME_AW(RpcBindingInqAuthInfo)
 
 RPCRTAPI RPC_STATUS RPC_ENTRY RpcCancelThread(void*);
+RPCRTAPI RPC_STATUS RPC_ENTRY RpcCancelThreadEx(void*,LONG);
 
 RPCRTAPI RPC_STATUS RPC_ENTRY
   RpcNetworkIsProtseqValidA( RPC_CSTR protseq );