diff --git a/gitlab-ci/Dockerfile b/gitlab-ci/Dockerfile
index d796828bb015976ef5f5af5e2618ebf7b61bf12d..6b586562a6cc41b4140ecc180d31d5a3d7240adc 100644
--- a/gitlab-ci/Dockerfile
+++ b/gitlab-ci/Dockerfile
@@ -13,8 +13,8 @@ ENV PERL_CPANM_HOME="/cpanm/"
 
 RUN apt-get update; \
     apt-get install -y --no-install-recommends gnupg wget; \
-    wget -O - http://sdvdebianrepo.slub-dresden.de/deb-repository/pub.gpg.key | apt-key add - ; \
-    echo "deb http://sdvdebianrepo.slub-dresden.de/deb-repository "${DEBIAN_RELEASE}" main" > /etc/apt/sources.list.d/slub.list;
+    wget -O - https://sdvdebianrepo.slub-dresden.de/deb-repository/pub.gpg.key | apt-key add - ; \
+    echo "deb https://sdvdebianrepo.slub-dresden.de/deb-repository "${DEBIAN_RELEASE}" main" > /etc/apt/sources.list.d/slub.list;
 
 RUN if [ -f /etc/apt/sources.list ]; then \
       sed -i -e "s/^\(\(deb\|Components\).*main\( contrib\)\?\)$/\1 non-free/g" /etc/apt/sources.list; \