diff --git a/.travis.yml b/.travis.yml
index 88a1850..479ab46 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,6 +1,7 @@
 language: node_js
 node_js: node
 addons:
-  firefox: "57.0"
+  firefox: '57.0'
 services:
   - xvfb
+dist: xenial