diff --git a/activemodel/lib/active_model/naming.rb b/activemodel/lib/active_model/naming.rb
index 8cf1a191f4b5aa4b58c37b57d7745063af1b8b5e..86f5c96af94a9f0ef3539a4b02dc7de2c13e49aa 100644
--- a/activemodel/lib/active_model/naming.rb
+++ b/activemodel/lib/active_model/naming.rb
@@ -216,6 +216,7 @@ def _singularize(string, replacement='_')
   module Naming
     def self.extended(base) #:nodoc:
       base.class_eval do
+        remove_possible_method(:model_name)
         delegate :model_name, to: :class
       end
     end