diff --git a/.gitlab-ci/Dockerfile b/.gitlab-ci/Dockerfile
index 2413b81f53..f4c97c99d4 100644
--- a/.gitlab-ci/Dockerfile
+++ b/.gitlab-ci/Dockerfile
@@ -70,4 +70,4 @@ RUN useradd -u $HOST_USER_ID -ms /bin/bash user
 USER user
 WORKDIR /home/user
 
-ENV LANG C.utf8
+ENV LANG C.UTF-8
diff --git a/.gitlab-ci/test-docker.sh b/.gitlab-ci/test-docker.sh
index dcac0a0c46..48b22d25ca 100755
--- a/.gitlab-ci/test-docker.sh
+++ b/.gitlab-ci/test-docker.sh
@@ -19,6 +19,5 @@ xvfb-run -a -s "-screen 0 1024x768x24" \
     meson test \
         --print-errorlogs \
         --suite=gtk+ \
-        --no-suite=gtk+:gdk \
         --no-suite=gtk+:gsk \
         --no-suite=gtk+:a11y