diff --git a/kernel/rtmutex-tester.c b/kernel/rtmutex-tester.c
index 015fc63..e3055ba 100644
--- a/kernel/rtmutex-tester.c
+++ b/kernel/rtmutex-tester.c
@@ -260,6 +260,7 @@
 	int ret;
 
 	current->flags |= PF_MUTEX_TESTER;
+	set_freezable();
 	allow_signal(SIGHUP);
 
 	for(;;) {