diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index dcfa741..bab2995 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -18,8 +18,7 @@ build-main:
   script:
     - docker build
       --build-arg BUILDKIT_INLINE_CACHE=1
-      --build-arg LDAP_PLUGIN_URL=$LDAP_PLUGIN_URL
-      --pull
+      --build-arg LDAP_PLUGIN_URL="${LDAP_PLUGIN_URL}"
       --cache-from $CI_REGISTRY_IMAGE:stage-src
       --target src
       -t "$CI_REGISTRY_IMAGE:stage-src"
@@ -37,8 +36,8 @@ build-main:
     - docker push "$CI_REGISTRY_IMAGE:stage-texlive-update-branch-$CI_COMMIT_REF_SLUG"
     - docker build
       --build-arg BUILDKIT_INLINE_CACHE=1
-      --build-arg login_text=$LOGIN_TEXT
-      --build-arg collab_text=$COLLAB_TEXT
+      --build-arg login_text="${LOGIN_TEXT}"
+      --build-arg collab_text="${COLLAB_TEXT}"
       --pull
       --cache-from $CI_REGISTRY_IMAGE
       --target app --squash