diff --git a/deploy.sh b/deploy.sh
index 3eb8203..d4b66bd 100755
--- a/deploy.sh
+++ b/deploy.sh
@@ -27,7 +27,7 @@ done <<< "$vers"
 read -p "Version to generate: " VERSION
 
 OTA_VERSION=`grep "VERSION=" bin/update.manifest | cut -d"=" -f2`
-OTA_VERSION=$(( "$OTA_VERSION" + 1 ))
+OTA_VERSION=$(( $OTA_VERSION + 1 ))
 
 sed -i.bak "s/#define OTA_VERSION .*/#define OTA_VERSION $OTA_VERSION/" include/config.h include/config.sample.h
 rm include/config.h.bak include/config.sample.h.bak