diff --git a/lib/stripe/card.rb b/lib/stripe/card.rb
index e96a0a8b..e53e4e16 100644
--- a/lib/stripe/card.rb
+++ b/lib/stripe/card.rb
@@ -13,7 +13,7 @@ module Stripe
     end
 
     def self.retrieve(id, opts=nil)
-      raise NotImplementedError.new("Cards cannot be retrieved without a customer ID. Retrieve a card using customer.cards.retrieve('card_id')")
+      raise NotImplementedError.new("Cards cannot be retrieved without a customer ID. Retrieve a card using customer.sources.retrieve('card_id')")
     end
   end
 end
diff --git a/test/stripe/customer_card_test.rb b/test/stripe/customer_card_test.rb
index 6435292d..da9b30a4 100644
--- a/test/stripe/customer_card_test.rb
+++ b/test/stripe/customer_card_test.rb
@@ -53,5 +53,11 @@ module Stripe
       card = c.sources.create(:source => "tok_41YJ05ijAaWaFS")
       assert_equal "test_card", card.id
     end
+
+    should "raise if accessing Stripe::Card.retrieve directly" do
+      assert_raises NotImplementedError do
+        Stripe::Card.retrieve "card_12345"
+      end
+    end
   end
 end