diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 2f40a2901b0a3c3ff8c1ca5a7cde437959f14ef8..8912d0a10a5457fe992dbc674820b70fbf3f247c 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -12,6 +12,7 @@ variables:
   QUILT_PATCHES: "debian/patches"
 
 before_script:
+  - echo "deb-src http://ftp.halifax.rwth-aachen.de/debian/ stretch main" > /etc/apt/sources.list.d/stretch_src.list
   - apt-get update
   - apt-get install -y apt-utils