diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nand/raw/atmel/nand-controller.c
index e7fdf532c5fe..8a19408abb63 100644
--- a/drivers/mtd/nand/raw/atmel/nand-controller.c
+++ b/drivers/mtd/nand/raw/atmel/nand-controller.c
@@ -1799,8 +1799,7 @@ atmel_nand_controller_legacy_add_nands(struct atmel_nand_controller *nc)
 	 * Legacy bindings only allow connecting a single NAND with a unique CS
 	 * line to the controller.
 	 */
-	nand = devm_kzalloc(nc->dev, sizeof(*nand) + sizeof(*nand->cs),
-			    GFP_KERNEL);
+	nand = devm_kzalloc(nc->dev, struct_size(nand, cs, 1), GFP_KERNEL);
 	if (!nand)
 		return -ENOMEM;