diff --git a/ipc/shm.c b/ipc/shm.c
index 6d16bb6..f8e10a2 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -279,7 +279,7 @@
 	if (size < SHMMIN || size > ns->shm_ctlmax)
 		return -EINVAL;
 
-	if (ns->shm_tot + numpages >= ns->shm_ctlall)
+	if (ns->shm_tot + numpages > ns->shm_ctlall)
 		return -ENOSPC;
 
 	shp = ipc_rcu_alloc(sizeof(*shp));