diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 42f987eb..2b9984e7 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -7,10 +7,8 @@ stages:
   - release
 
 before_script:
-  - echo deb http://deb.debian.org/debian bullseye-backports main contrib non-free >> /etc/apt/sources.list
   - apt update
-  - env apt install --yes python3-dev libldap2-dev libsasl2-dev libssl-dev
-  - env DEBIAN_FRONTEND=noninteractive apt -t bullseye-backports install --yes slapd ldap-utils
+  - env DEBIAN_FRONTEND=noninteractive apt install --yes python3-dev libldap2-dev libsasl2-dev libssl-dev slapd ldap-utils
   - curl -O https://bootstrap.pypa.io/get-pip.py
   - python get-pip.py
   - pip install --upgrade tox "poetry>1.3.0" coveralls pyyaml tomli