diff --git a/.travis.yml b/.travis.yml
index 041fa86db97..db5b7136fbd 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,6 +24,7 @@ env:
 matrix:
   include:
     - php: 5.5
+      dist: trusty
       env: DB="postgresql" DB_USER="postgres"
     - php: 5.6
       env: DB="mysql" DB_USER="root"