--- a/tests/mutex6r.c
+++ b/tests/mutex6r.c
@@ -85,7 +85,7 @@
 
   assert(pthread_create(&t, NULL, locker, NULL) == 0);
 
-  assert(pthread_join(t, (void *) &result) == 0);
+  assert(pthread_join(t, &result) == 0);
   assert((int)(size_t)result == 555);
 
   assert(lockCount == 2);