diff --git a/drivers/mtd/mtdoops.c b/drivers/mtd/mtdoops.c
index cea9279ceabf..f3cdce9a85a6 100644
--- a/drivers/mtd/mtdoops.c
+++ b/drivers/mtd/mtdoops.c
@@ -372,7 +372,7 @@ static void mtdoops_notify_add(struct mtd_info *mtd)
 
 	/* oops_page_used is a bit field */
 	cxt->oops_page_used = vmalloc(DIV_ROUND_UP(mtdoops_pages,
-			BITS_PER_LONG));
+			BITS_PER_LONG) * sizeof(unsigned long));
 	if (!cxt->oops_page_used) {
 		printk(KERN_ERR "mtdoops: could not allocate page array\n");
 		return;