diff --git a/gulpfile.js b/gulpfile.js
index 784cda6..906ce73 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -24,7 +24,7 @@ var opts = {
   concatName: 'animate.css',
 
   autoprefixer: {
-    browsers: ['last 2 versions'],
+    browsers: ['> 1%, last 2 versions, Firefox ESR'],
     cascade: false
   },