diff --git a/testem.json b/testem.json
index 34cb656b..d649b554 100644
--- a/testem.json
+++ b/testem.json
@@ -8,7 +8,8 @@
   ],
   "launch_in_dev": [
     "PhantomJS",
-    "Chrome"
+    "Chrome",
+    "Firefox"
   ],
   "launchers": {
     "SL_chrome": {