diff --git a/404.md b/404.md
index beffa9d763..6889b472a1 100644
--- a/404.md
+++ b/404.md
@@ -4,7 +4,17 @@ title: 404 Error!
 permalink: /404.html
 ---
 
+<script language="JavaScript">
+$( document ).ready(function() {
+  if (window.location.href.indexOf(".html") > -1) {
+    var forwardingURL=window.location.href.replace(".html","");
+    window.location.replace(forwardingURL);
+  }
+});
+</script>
+
 Sorry, this page was not found. :( 
 
 You can let us know by filling out the "I wish this page" text field at
-the bottom of this page. Maybe try: "I wish this page _existed_."
\ No newline at end of file
+the bottom of this page. Maybe try: "I wish this page _existed_."
+