diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 99ab56058052641cad8098f628df4679b7b9eb79..68823695926da01471cb18fa23de6d5192895ba4 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -22,7 +22,7 @@ doxygen:
   tags:
     - documentation
   before_script:
-    - apt-get install doxygen
+    - apt-get update && apt-get install doxygen
   script:
     - git clone https://gitlab-ci-token:${CI_JOB_TOKEN}@git.rwth-aachen.de/unicado/libraries
     - doxygen libraries/aircraftGeometry2/doc/Doxyfile