diff --git a/app/controllers/wiki_page_versions_controller.rb b/app/controllers/wiki_page_versions_controller.rb
index 8a7fa7273..8b57fe1e6 100644
--- a/app/controllers/wiki_page_versions_controller.rb
+++ b/app/controllers/wiki_page_versions_controller.rb
@@ -20,5 +20,11 @@ class WikiPageVersionsController < ApplicationController
 
     @thispage = WikiPageVersion.find(params[:thispage])
     @otherpage = WikiPageVersion.find(params[:otherpage])
+
+    if @thispage.id < @otherpage.id
+      @thispage, @otherpage = @otherpage, @thispage
+    end
+
+    respond_with([@thispage, @otherpage])
   end
 end