diff --git a/Gemfile.rails-3.1.4 b/Gemfile.rails-3.1.4
index 47cd12d0..a2844fd6 100644
--- a/Gemfile.rails-3.1.4
+++ b/Gemfile.rails-3.1.4
@@ -8,7 +8,7 @@ gem 'rails', '3.1.4'
 gem 'sqlite3'
 gem 'mysql'
 gem 'activerecord-import'
-gem 'mongoid'
+gem 'mongoid', '2.4.10'
 gem 'bson_ext'
 
 gem "rspec"
diff --git a/Gemfile.rails-3.1.4.lock b/Gemfile.rails-3.1.4.lock
index 840e99b6..f1dc1d08 100644
--- a/Gemfile.rails-3.1.4.lock
+++ b/Gemfile.rails-3.1.4.lock
@@ -65,7 +65,7 @@ GEM
       activemodel (~> 3.1)
       mongo (~> 1.3)
       tzinfo (~> 0.3.22)
-    multi_json (1.3.5)
+    multi_json (1.3.6)
     mysql (2.8.1)
     perftools.rb (2.0.0)
     polyglot (0.3.3)
@@ -126,7 +126,7 @@ DEPENDENCIES
   bullet!
   guard
   guard-rspec
-  mongoid
+  mongoid (= 2.4.10)
   mysql
   perftools.rb
   rails (= 3.1.4)