diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 05aafe43b..6aac589c1 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,9 +1,25 @@
 stages:
   - postinstall
   - tests
+  - lint
 
-.tests:
+########################################
+# POSTINSTALL
+########################################
+
+postinstall:
+  image: before-postinstall
+  stage: postinstall
+  script:
+    - yunohost tools postinstall -d domain.tld -p the_password --ignore-dyndns
+
+########################################
+# TESTS
+########################################
+
+.test-stage:
   image: after-postinstall
+  stage: tests
   before_script:
     - apt-get install python-pip -y
     - mkdir -p .pip
@@ -25,77 +41,90 @@ stages:
       - src/yunohost/tests/apps
     key: "$CI_JOB_STAGE-$CI_COMMIT_REF_SLUG"
 
-postinstall:
-  image: before-postinstall
-  stage: postinstall
-  script:
-    - yunohost tools postinstall -d domain.tld -p the_password --ignore-dyndns
-
 root-tests:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - py.test tests
 
 test-apps:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_apps.py
 
 test-appscatalog:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_appscatalog.py
 
 test-appurl:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_appurl.py
 
 test-backuprestore:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_backuprestore.py
 
 test-changeurl:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_changeurl.py
 
 test-permission:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_permission.py
 
 test-settings:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_settings.py
 
 test-user-group:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_user-group.py
     
 test-regenconf:
-  extends: .tests
-  stage: tests
+  extends: .test-stage
   script:
     - cd src/yunohost
     - py.test tests/test_regenconf.py
+
+########################################
+# LINTER
+########################################
+
+.lint-stage:
+  image: before-postinstall
+  stage: lint
+  before_script:
+    - apt-get install python-pip -y
+    - mkdir -p .pip
+    - pip install -U pip
+    - hash -d pip
+    - pip --cache-dir=.pip install flake8 blake
+  cache:
+    paths: 
+      - .pip
+      - src/yunohost/tests/apps
+    key: "$CI_JOB_STAGE-$CI_COMMIT_REF_SLUG"
+
+lint:
+  extends: .lint-stage
+  script:
+    - flake8 src tests data
+
+format-check:
+  extends: .lint-stage
+  script:
+    - black {posargs:--check --diff} src tests data
\ No newline at end of file