diff --git a/app/models/impressionist/impressionable.rb b/app/models/impressionist/impressionable.rb
index a6284f6..e4aeae3 100644
--- a/app/models/impressionist/impressionable.rb
+++ b/app/models/impressionist/impressionable.rb
@@ -1,10 +1,6 @@
 module Impressionist
   module Impressionable
-
-    def self.included(base)
-      base.extend ClassMethods
-      base.send(:include, InstanceMethods)
-    end
+    extend ActiveSupport::Concern
 
     module ClassMethods
       attr_accessor :cache_options
@@ -28,44 +24,41 @@ module Impressionist
       end
     end
 
-    module InstanceMethods
-      def impressionable?
-        true
-      end
-
-      def impressionist_count(options={})
-        options.reverse_merge!(:filter=>:request_hash, :start_date=>nil, :end_date=>Time.now)
-        imps = options[:start_date].blank? ? impressions : impressions.where("created_at>=? and created_at<=?",options[:start_date],options[:end_date])
-        if options[:filter]!=:all
-          imps = imps.select(options[:filter]).group(options[:filter])
-        end
-        imps.all.size
-      end
-
-      def update_counter_cache
-        cache_options = self.class.counter_cache_options
-        column_name = cache_options[:column_name].to_sym
-        count = cache_options[:unique] ? impressionist_count(:filter => :ip_address) : impressionist_count
-        update_attribute(column_name, count)
-      end
-
-      # OLD METHODS - DEPRECATE IN V0.5
-      def impression_count(start_date=nil,end_date=Time.now)
-        impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=>:all})
-      end
-
-      def unique_impression_count(start_date=nil,end_date=Time.now)
-        impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :request_hash})
-      end
-
-      def unique_impression_count_ip(start_date=nil,end_date=Time.now)
-        impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :ip_address})
-      end
-
-      def unique_impression_count_session(start_date=nil,end_date=Time.now)
-        impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :session_hash})
-      end
+    def impressionable?
+      true
     end
 
+    def impressionist_count(options={})
+      options.reverse_merge!(:filter=>:request_hash, :start_date=>nil, :end_date=>Time.now)
+      imps = options[:start_date].blank? ? impressions : impressions.where("created_at>=? and created_at<=?",options[:start_date],options[:end_date])
+      if options[:filter]!=:all
+        imps = imps.select(options[:filter]).group(options[:filter])
+      end
+      imps.all.size
+    end
+
+    def update_counter_cache
+      cache_options = self.class.counter_cache_options
+      column_name = cache_options[:column_name].to_sym
+      count = cache_options[:unique] ? impressionist_count(:filter => :ip_address) : impressionist_count
+      update_attribute(column_name, count)
+    end
+
+    # OLD METHODS - DEPRECATE IN V0.5
+    def impression_count(start_date=nil,end_date=Time.now)
+      impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=>:all})
+    end
+
+    def unique_impression_count(start_date=nil,end_date=Time.now)
+      impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :request_hash})
+    end
+
+    def unique_impression_count_ip(start_date=nil,end_date=Time.now)
+      impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :ip_address})
+    end
+
+    def unique_impression_count_session(start_date=nil,end_date=Time.now)
+      impressionist_count({:start_date=>start_date, :end_date=>end_date, :filter=> :session_hash})
+    end
   end
 end
diff --git a/test_app/Gemfile b/test_app/Gemfile
index 2c1ba22..6eb41ea 100644
--- a/test_app/Gemfile
+++ b/test_app/Gemfile
@@ -2,11 +2,9 @@ source 'https://rubygems.org'
 
 gem 'rails', '3.2.2'
 
-# Bundle edge Rails instead:
-# gem 'rails', :git => 'git://github.com/rails/rails.git'
-
 gem 'impressionist', :path => '../'
 
+gem 'pg'
 gem 'sqlite3'
 
 gem 'json'