diff --git a/services/scripts/build_base_image.sh b/services/scripts/build_base_image.sh
--- a/services/scripts/build_base_image.sh
+++ b/services/scripts/build_base_image.sh
@@ -2,10 +2,10 @@
 
 set -e
 
-if [ "$#" -gt 1 ]; then
+if [[ "$#" -gt 1 ]]; then
   echo "usage: $0 [TAG]"
   exit 1
 fi
 
 tag=${1:-"1.1"}
-docker build -t commapp/services-base:${tag} base-image
+docker build -t commapp/services-base:"${tag}" base-image