diff --git a/actionpack/test/activerecord/active_record_store_test.rb b/actionpack/test/activerecord/active_record_store_test.rb
index 34f1880..9febc1e 100644
--- a/actionpack/test/activerecord/active_record_store_test.rb
+++ b/actionpack/test/activerecord/active_record_store_test.rb
@@ -27,9 +27,9 @@ class ActiveRecordStoreTest < ActionController::IntegrationTest
     end
 
     def call_reset_session
-      session[:bar]
+      session[:foo]
       reset_session
-      session[:bar] = "baz"
+      session[:foo] = "baz"
       head :ok
     end
 
@@ -90,7 +90,7 @@ class ActiveRecordStoreTest < ActionController::IntegrationTest
 
       get '/get_session_value'
       assert_response :success
-      assert_equal 'foo: nil', response.body
+      assert_equal 'foo: "baz"', response.body
 
       get '/get_session_id'
       assert_response :success
diff --git a/activerecord/lib/active_record/session_store.rb b/activerecord/lib/active_record/session_store.rb
index 8fc5c9e..c397e98 100644
--- a/activerecord/lib/active_record/session_store.rb
+++ b/activerecord/lib/active_record/session_store.rb
@@ -295,7 +295,7 @@ module ActiveRecord
 
       def set_session(env, sid, session_data)
         Base.silence do
-          record = env[SESSION_RECORD_KEY] ||= find_session(sid)
+          record = get_session_model(env, sid)
           record.data = session_data
           return false unless record.save
 
@@ -309,6 +309,14 @@ module ActiveRecord
 
         return true
       end
+      
+      def get_session_model(env, sid)
+        if env[ENV_SESSION_OPTIONS_KEY][:id].nil?
+          env[SESSION_RECORD_KEY] = find_session(sid)
+        else
+          env[SESSION_RECORD_KEY] ||= find_session(sid)
+        end
+      end
 
       def find_session(id)
         @@session_class.find_by_session_id(id) ||