--- threading_pthread.c.orig	Tue Sep 23 15:07:41 2014
+++ threading_pthread.c	Tue Sep 23 15:09:45 2014
@@ -54,7 +54,7 @@ thread_start (void (*fn)(void *ctx), void *ctx) {
         fprintf (stderr, "pthread_attr_destroy failed: %s\n", strerror (s));
         return 0;
     }
-    return tid;
+    return (intptr_t)tid;
 }
 
 intptr_t
