diff --git a/ipc/util.h b/ipc/util.h
index 1296691..791c5c0 100644
--- a/ipc/util.h
+++ b/ipc/util.h
@@ -113,6 +113,8 @@
 void kernel_to_ipc64_perm(struct kern_ipc_perm *in, struct ipc64_perm *out);
 void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
 void ipc_update_perm(struct ipc64_perm *in, struct kern_ipc_perm *out);
+struct kern_ipc_perm *ipcctl_pre_down(struct ipc_ids *ids, int id, int cmd,
+				      struct ipc64_perm *perm, int extra_perm);
 
 #if defined(__ia64__) || defined(__x86_64__) || defined(__hppa__) || defined(__XTENSA__)
   /* On IA-64, we always use the "64-bit version" of the IPC structures.  */