diff --git a/.travis.yml b/.travis.yml
index 84af0d7d..958744c0 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -7,6 +7,7 @@ dist: trusty
 
 addons:
   chrome: stable
+  firefox: latest
 
 cache:
   yarn: true
diff --git a/testem.js b/testem.js
index 028b4f35..98f8c2a4 100644
--- a/testem.js
+++ b/testem.js
@@ -5,12 +5,19 @@ module.exports = {
   test_page: 'tests/index.html?hidepassed',
   disable_watching: true,
   launch_in_ci: [
-    'Chrome'
+    'Chrome',
+    'Firefox'
   ],
   launch_in_dev: [
     'Chrome'
   ],
   browser_args: {
+    Firefox: {
+      mode: 'ci',
+      args: [
+        '-headless'
+      ]
+    },
     Chrome: {
       mode: 'ci',
       args: [