diff --git a/actionpack/test/activerecord/active_record_store_test.rb b/actionpack/test/activerecord/active_record_store_test.rb
index 6a75e6050d741..7998f9c22f499 100644
--- a/actionpack/test/activerecord/active_record_store_test.rb
+++ b/actionpack/test/activerecord/active_record_store_test.rb
@@ -21,6 +21,11 @@ def get_session_value
       render :text => "foo: #{session[:foo].inspect}"
     end
 
+    def call_reset_session
+      reset_session
+      head :ok
+    end
+
     def rescue_action(e) raise end
   end
 
@@ -61,6 +66,22 @@ def test_getting_nil_session_value
     end
   end
 
+  def test_setting_session_value_after_session_reset
+    with_test_route_set do
+      get '/set_session_value'
+      assert_response :success
+      assert cookies['_session_id']
+
+      get '/call_reset_session'
+      assert_response :success
+      assert_not_equal [], headers['Set-Cookie']
+
+      get '/get_session_value'
+      assert_response :success
+      assert_equal 'foo: nil', response.body
+    end
+  end
+
   def test_prevents_session_fixation
     with_test_route_set do
       get '/set_session_value'
diff --git a/activerecord/lib/active_record/session_store.rb b/activerecord/lib/active_record/session_store.rb
index de199d30bf062..3cc4640f42643 100644
--- a/activerecord/lib/active_record/session_store.rb
+++ b/activerecord/lib/active_record/session_store.rb
@@ -287,8 +287,7 @@ def destroy
       def get_session(env, sid)
         Base.silence do
           sid ||= generate_sid
-          session = @@session_class.find_by_session_id(sid)
-          session ||= @@session_class.new(:session_id => sid, :data => {})
+          session = find_session(sid)
           env[SESSION_RECORD_KEY] = session
           [sid, session.data]
         end
@@ -296,7 +295,7 @@ def get_session(env, sid)
 
       def set_session(env, sid, session_data)
         Base.silence do
-          record = env[SESSION_RECORD_KEY]
+          record = env[SESSION_RECORD_KEY] ||= find_session(sid)
           record.data = session_data
           return false unless record.save
 
@@ -310,5 +309,10 @@ def set_session(env, sid, session_data)
 
         return true
       end
+
+      def find_session(id)
+        @@session_class.find_by_session_id(id) ||
+          @@session_class.new(:session_id => id, :data => {})
+      end
   end
 end