diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index f7267ba01cedfe352e2005f6c69990d7461c9cce..48815f2f68599afc9b33e2bc92ca0c103d0a83a6 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -10,12 +10,28 @@ before_script:
 
 # Defines stages which are to be executed
 stages:
+  - syntax
   - build
   - test
   - publish
   - upgradetest
 
 
+#
+### Stage syntax
+#
+
+syntax:codestyle:
+  stage: syntax
+  image: bobey/docker-gitlab-ci-runner-php5.6
+  allow_failure: false
+
+  script:
+    - composer require phplint/phplint
+    - echo "Syntax checking PHP files"
+    - echo "For more information http://www.icosaedro.it/phplint/"
+    - vendor/bin/phplint ./ --exclude "vendor"
+
 #
 ### Stage "build"
 #
@@ -49,10 +65,13 @@ build:deb:
 test:debian-jessie-aegir3-apt:
   stage: test
   image: debian:jessie
+  allow_failure: false
   dependencies:
     - build:deb
-  only:
+  when: manual
+  except:
     - 7.x-3.x
+    - /^7\.x-3\.\d+\.x/
 
   before_script:
     - apt-get update
@@ -66,7 +85,7 @@ test:debian-jessie-aegir3-apt:
 test:debian-stretch-aegir3-apt:
   stage: test
   image: debian:stretch
-  allow_failure: true
+  allow_failure: false
   dependencies:
     - build:deb
 
@@ -82,10 +101,14 @@ test:debian-stretch-aegir3-apt:
 test:ubuntu-xenial-aegir3-apt:
   stage: test
   image: ubuntu:xenial
+  allow_failure: false
   dependencies:
     - build:deb
-  only:
+
+  when: manual
+  except:
     - 7.x-3.x
+    - /^7\.x-3\.\d+\.x/
 
   before_script:
     - apt-get update
@@ -99,9 +122,14 @@ test:ubuntu-xenial-aegir3-apt:
 test:ubuntu-artful-aegir3-apt:
   stage: test
   image: ubuntu:artful
+  allow_failure: true
   dependencies:
     - build:deb
-  allow_failure: true
+
+  when: manual
+  except:
+    - 7.x-3.x
+    - /^7\.x-3\.\d+\.x/
 
   before_script:
     - apt-get update
@@ -153,7 +181,6 @@ publish:unstable-repo:
   stage: publish
   dependencies:
     - build:deb
-  allow_failure: true
 
   only:
     - 7.x-3.x
@@ -191,6 +218,7 @@ upgradetest:debian-jessie-aegir3-apt-upgrade:
   image: debian:jessie
   dependencies:
     - publish:unstable-repo
+  allow_failure: false
 
   when: manual