diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 6f7826dca53f79fcdbe036012eb703ee4ae5f605..88ff820707587dd1a86e868f83c7e243b3d1c07c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -40,6 +40,7 @@ create_phpstan_rapport:
   script:
     - test -d ../dev-tools/ && rm -Rf ../dev-tools/
     - git clone --depth 1 https://gitlab.fusiondirectory.org/fusiondirectory/dev-tools.git ../dev-tools
+    - apt install libphp-phpmailer
     - cp ../dev-tools/phpstan/fusiondirectory-integrator/*.neon .
     - /root/.composer/vendor/bin/phpstan analyse -c phpstan.neon