diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 4e59f83..aae3573 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,5 +1,11 @@
+variables:
+  DOCKER_TLS_CERTDIR: "/certs"
+
+services:
+  - docker:20.10.0-dind
+
 .build: &build
-  image: docker:latest
+  image: docker:20.10.0
   stage: build
   script:
     - docker login -u gitlab-ci-token -p "${CI_JOB_TOKEN}" "${CI_REGISTRY}"
@@ -10,7 +16,7 @@
     - if [[ "${CI_COMMIT_REF_SLUG}" == "main" ]]; then docker tag "${CI_REGISTRY_IMAGE}/${NAME}:${CI_COMMIT_REF_SLUG}" "${CI_REGISTRY_IMAGE}/${NAME}:latest" && docker push "${CI_REGISTRY_IMAGE}/${NAME}:latest"; fi
 
 signal-server:
-  image: docker:latest
+  image: docker:20.10.0
   stage: build
   script:
     - docker login -u gitlab-ci-token -p ${CI_JOB_TOKEN} ${CI_REGISTRY}
@@ -24,11 +30,11 @@ signal-server:
     - echo "docker pull ${CI_REGISTRY_IMAGE}/signal-server:${VERSION}"
   allow_failure: true
 
-testhelper:
+test-helper:
   <<: *build
   variables:
-    DOCKERFILE: "testhelper.Dockerfile"
-    NAME: "testhelper"
+    DOCKERFILE: "test-helper.Dockerfile"
+    NAME: "test-helper"
   allow_failure: true
 
 builder-image:aarch64: