diff --git a/common/cmd_nand.c b/common/cmd_nand.c
index b248a2c..8d6c959 100644
--- a/common/cmd_nand.c
+++ b/common/cmd_nand.c
@@ -350,10 +350,10 @@
 		} else if (s != NULL && !strcmp(s, ".oob")) {
 			/* read out-of-band data */
 			if (read)
-				ret = nand->read_oob(nand, off, size, &size,
+				ret = nand->read_oob(nand, off, size, (size_t *) &size,
 						     (u_char *) addr);
 			else
-				ret = nand->write_oob(nand, off, size, &size,
+				ret = nand->write_oob(nand, off, size, (size_t *) &size,
 						      (u_char *) addr);
 		} else {
 			if (read)