1 files changed, 3 insertions, 7 deletions
diff --git a/activerecord/lib/active_record/reflection.rb b/activerecord/lib/active_record/reflection.rb
index 70e2487891..cb240229a5 100644
--- a/activerecord/lib/active_record/reflection.rb
+++ b/activerecord/lib/active_record/reflection.rb
@@ -826,13 +826,9 @@ module ActiveRecord
       end
 
       def source_type_scope
-        @source_type_lambda ||= begin
-          type = foreign_type
-          source_type = options[:source_type]
-          lambda { |object|
-            where(type => source_type)
-          }
-        end
+        type = foreign_type
+        source_type = options[:source_type]
+        lambda { |object| where(type => source_type) }
       end
 
       def has_scope?