diff --git a/kernel/pid.c b/kernel/pid.c
index eb66bd2..c6e3f9f 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -365,7 +365,7 @@
 }
 EXPORT_SYMBOL_GPL(find_get_pid);
 
-struct pid_namespace *copy_pid_ns(int flags, struct pid_namespace *old_ns)
+struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
 {
 	BUG_ON(!old_ns);
 	get_pid_ns(old_ns);