Index: kernel/generic/src/synch/futex.c
===================================================================
--- kernel/generic/src/synch/futex.c	(revision 87a2f9b316ec093fffb699d0be0969f90507c629)
+++ kernel/generic/src/synch/futex.c	(revision 1626cd4d3269f272038f96a6fa17c3536f1b084c)
@@ -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;