diff --git a/kernel/ptrace.c b/kernel/ptrace.c
index 61c78b2..082c320 100644
--- a/kernel/ptrace.c
+++ b/kernel/ptrace.c
@@ -181,8 +181,8 @@
 	 * interference; SUID, SGID and LSM creds get determined differently
 	 * under ptrace.
 	 */
-	retval = mutex_lock_interruptible(&task->cred_guard_mutex);
-	if (retval < 0)
+	retval = -ERESTARTNOINTR;
+	if (mutex_lock_interruptible(&task->cred_guard_mutex))
 		goto out;
 
 	task_lock(task);