diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1fa892c63428f0634fbfe3c0ba3cf1469351b314..831ac5559f7a3d4b799e270f72ba21904d38299e 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,6 +1,6 @@
 before_script:
-    -yum install make
-    -yum install which
+    #pre-installation script
+    - yum install make which -y
 
 centos7-gcc48:
   tags: