diff --git a/base/services/wlansvc/rpcserver.c b/base/services/wlansvc/rpcserver.c
index bb010368669..4528481dfe9 100644
--- a/base/services/wlansvc/rpcserver.c
+++ b/base/services/wlansvc/rpcserver.c
@@ -525,7 +525,7 @@ DWORD _RpcGetSecuritySettings(
     return ERROR_CALL_NOT_IMPLEMENTED;
 }
 
-void __RPC_FAR * __RPC_USER midl_user_allocate(SIZE_T len)
+void __RPC_FAR * __RPC_USER midl_user_allocate(size_t len)
 {
     return HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY, len);
 }