diff --git a/.travis.yml b/.travis.yml
index 9e7a449010..16086e2663 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,3 +1,4 @@
+services: memcache
 script: 'ci/travis.rb'
 before_install:
   - travis_retry gem install bundler
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 03b5bdc46c..5465a7bfd7 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -621,7 +621,7 @@ module ActiveRecord
       end
 
       def source_reflection_name # :nodoc:
-        return @source_reflection_name if @source_reflection_name
+        return @source_reflection_name.to_sym if @source_reflection_name
 
         names = [name.to_s.singularize, name].collect { |n| n.to_sym }.uniq
         names = names.find_all { |n|
diff --git a/activerecord/test/models/tag.rb b/activerecord/test/models/tag.rb
index a581b381e8..80d4725f7e 100644
--- a/activerecord/test/models/tag.rb
+++ b/activerecord/test/models/tag.rb
@@ -3,5 +3,5 @@ class Tag < ActiveRecord::Base
   has_many :taggables, :through => :taggings
   has_one  :tagging
 
-  has_many :tagged_posts, :through => :taggings, :source => :taggable, :source_type => 'Post'
-end
\ No newline at end of file
+  has_many :tagged_posts, :through => :taggings, :source => 'taggable', :source_type => 'Post'
+end