diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 98ed42a00692f3994c51f35717c7617bdaf79cfa..bdb610c1559f719316384d719cca5669e0e43dcb 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,7 +12,7 @@ before_script:
 
   # install the required packages for the running CI tests
   - |
-    apt-get -yqqf install lsb-release zip unzip subversion mysql-client libicu-dev --fix-missing
+    apt-get -yqqf install lsb-release zip unzip subversion mysql-client libicu-dev libpng-dev --fix-missing
 
     if [[ $(lsb_release -a) =~ "stretch" ]]; then
       apt-get -yqqf install default-libmysqlclient-dev --fix-missing