Index: kernel/generic/src/synch/futex.c
===================================================================
--- kernel/generic/src/synch/futex.c	(revision 759ea0d4a36cb6f7089767643dd0afd7ed4e7586)
+++ kernel/generic/src/synch/futex.c	(revision 78d50bd06d1f1eb12182cb42a78d0182b9256f3d)
@@ -400,5 +400,13 @@
 		return (sysarg_t) ENOENT;
 
+#ifdef CONFIG_UDEBUG
+	udebug_stoppable_begin();
+#endif
+
 	int rc = waitq_sleep_timeout(&futex->wq, 0, SYNCH_FLAGS_INTERRUPTIBLE); 
+
+#ifdef CONFIG_UDEBUG
+	udebug_stoppable_end();
+#endif
 
 	return (sysarg_t) rc;