diff --git a/ipc/util.h b/ipc/util.h
index f37d160..0e3d790 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -124,6 +124,8 @@
 extern struct msg_msg *load_msg(const void __user *src, int len);
 extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
 
+extern void recompute_msgmni(struct ipc_namespace *);
+
 static inline int ipc_buildid(int id, int seq)
 {
 	return SEQ_MULTIPLIER * seq + id;