mongoid-undo.gemspec in mongoid-undo-0.4.0 vs mongoid-undo.gemspec in mongoid-undo-0.5.0

@@ -12,7 +12,7 @@
 
   gem.files         = `git ls-files`.split("\n")
   gem.require_path  = 'lib'
 
   gem.add_dependency 'activesupport'
-  gem.add_dependency 'mongoid'
+  gem.add_dependency 'mongoid', '>= 3.0.10', '< 4.0'
 end