diff --git a/Utilities/cmxmlrpc/win32_pthreads.c b/Utilities/cmxmlrpc/win32_pthreads.c
index b45363df13..a072f9b48d 100644
--- a/Utilities/cmxmlrpc/win32_pthreads.c
+++ b/Utilities/cmxmlrpc/win32_pthreads.c
@@ -41,7 +41,7 @@ int pthread_create(pthread_t *new_thread_ID,
           pthread_func start_func, void *arg)
 {
         HANDLE hThread;
-        DWORD dwThreadID;
+        unsigned dwThreadID;
 
         XMLRPC_ASSERT (attr == NULL); /* unimplemented. */
     XMLRPC_ASSERT_PTR_OK(new_thread_ID);