diff --git a/lib/pastebinner.rb b/lib/pastebinner.rb
index 3bbbecb..27f3f51 100755
--- a/lib/pastebinner.rb
+++ b/lib/pastebinner.rb
@@ -115,8 +115,10 @@ class Pastebinner
   end
 
   # scraped keys difference returned
-  def get_key_diffs(keys1, keys2)
-    keys1 - keys2 | keys2 - keys1
+  # https://stackoverflow.com/questions/8639857/rails-3-how-to-get-the-difference-between-two-arrays
+  # note ruby 2.6 has a method for this - https://github.com/ruby/ruby/blob/trunk/array.c#L4450-L4563
+  def difference(a, b)
+    a - b | b - a
   end
 
   def raw_paste_data(unique_paste_key)