diff --git a/utils/OSThread_POSIX.c b/utils/OSThread_POSIX.c
index 0be322c9..e3cd1e2d 100644
--- a/utils/OSThread_POSIX.c
+++ b/utils/OSThread_POSIX.c
@@ -95,7 +95,7 @@ UINT64 OSThread_GetID(const OS_THREAD* thr)
 #elif defined (__HAIKU__)
 	return get_pthread_thread_id (thr->id);
 #else
-	return thr->id;
+	return (UINT64)thr->id;
 #endif
 }