diff --git a/ipc/shm.c b/ipc/shm.c
index cb858df..8247c49 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -462,7 +462,7 @@
 	size_t size = params->u.size;
 	int error;
 	struct shmid_kernel *shp;
-	int numpages = (size + PAGE_SIZE -1) >> PAGE_SHIFT;
+	size_t numpages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
 	struct file * file;
 	char name[13];
 	int id;