1 files changed, 10 insertions, 1 deletions
diff --git a/activesupport/lib/active_support/core_ext/class/attribute.rb b/activesupport/lib/active_support/core_ext/class/attribute.rb
index f2b7bb3ef1..802d988af2 100644
--- a/activesupport/lib/active_support/core_ext/class/attribute.rb
+++ b/activesupport/lib/active_support/core_ext/class/attribute.rb
@@ -75,11 +75,15 @@ class Class
     instance_predicate = options.fetch(:instance_predicate, true)
 
     attrs.each do |name|
+      remove_possible_singleton_method(name)
       define_singleton_method(name) { nil }
+
+      remove_possible_singleton_method("#{name}?")
       define_singleton_method("#{name}?") { !!public_send(name) } if instance_predicate
 
       ivar = "@#{name}"
 
+      remove_possible_singleton_method("#{name}=")
       define_singleton_method("#{name}=") do |val|
         singleton_class.class_eval do
           remove_possible_method(name)
@@ -110,10 +114,15 @@ class Class
             self.class.public_send name
           end
         end
+
+        remove_possible_method "#{name}?"
         define_method("#{name}?") { !!public_send(name) } if instance_predicate
       end
 
-      attr_writer name if instance_writer
+      if instance_writer
+        remove_possible_method "#{name}="
+        attr_writer name
+      end
     end
   end
 end