diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index bdbd55c..fc943aa 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -13,6 +13,9 @@ stages:
 
 build:
   stage: build
+  only:
+    refs:
+      - master
   script:
     - docker pull $CI_REGISTRY_IMAGE_NG || true
     - docker build --cache-from $CI_REGISTRY_IMAGE_NG -f ng.Dockerfile -t $CI_REGISTRY_IMAGE_NG .