diff --git a/package/base-files/files/lib/functions/system.sh b/package/base-files/files/lib/functions/system.sh
index 9b9d03df7b..2a43d18d33 100644
--- a/package/base-files/files/lib/functions/system.sh
+++ b/package/base-files/files/lib/functions/system.sh
@@ -40,7 +40,7 @@ mtd_get_mac_ascii() {
 
 mtd_get_mac_text() {
 	local mtdname=$1
-	local offset=$2
+	local offset=$(($2))
 	local part
 	local mac_dirty