diff --git a/lib/jekyll/entry_filter.rb b/lib/jekyll/entry_filter.rb
index b8f4e044..4f527edd 100644
--- a/lib/jekyll/entry_filter.rb
+++ b/lib/jekyll/entry_filter.rb
@@ -53,7 +53,7 @@ module Jekyll
     end
 
     def backup?(entry)
-      entry[-1..-1] == "~"
+      entry.end_with?("~")
     end
 
     def excluded?(entry)