diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 78e1472..727187f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -1362,7 +1362,7 @@
 }
 
 SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
-		unsigned long, mode, unsigned long __user *, nmask,
+		unsigned long, mode, const unsigned long __user *, nmask,
 		unsigned long, maxnode, unsigned, flags)
 {
 	nodemask_t nodes;