diff --git a/main-window.js b/main-window.js
index 3e0b591ab..e981f7f59 100644
--- a/main-window.js
+++ b/main-window.js
@@ -16,7 +16,7 @@ var requireStyle = require('require-style')
 
 try {
   var mouseForwardBack = require('mouse-forward-back')
-} catch (er) {
+} catch (err) {
   mouseForwardBack = false
 }