diff --git a/activesupport/lib/active_support/core_ext/class/attribute.rb b/activesupport/lib/active_support/core_ext/class/attribute.rb
index 688cba03dba74fea10a6dc4039dbfd06d2c8ea0e..8f0f50919ff0de57a9f6a3eeddfbb7b0bc0e90e1 100644
--- a/activesupport/lib/active_support/core_ext/class/attribute.rb
+++ b/activesupport/lib/active_support/core_ext/class/attribute.rb
@@ -75,6 +75,7 @@ def self.#{name}=(val)
           val
         end
 
+        remove_method :#{name} if method_defined?(:#{name})
         def #{name}
           defined?(@#{name}) ? @#{name} : singleton_class.#{name}
         end