diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 0083b4ee4f3377c5a3d9c2963ccd53e15dc21ad5..372e0e38f59b323f4388c6d96416ea5ea35f3c69 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -1160,6 +1160,10 @@ static void mxc_nand_command(struct mtd_info *mtd, unsigned command,
 		memcpy32_fromio(host->data_buf, host->main_area0, 512);
 		host->buf_start = 0;
 		break;
+	default:
+		WARN_ONCE(1, "Unimplemented command (cmd=%u)\n",
+			  command);
+		break;
 	}
 }