diff --git a/activemodel/lib/active_model/secure_password.rb b/activemodel/lib/active_model/secure_password.rb
index <HASH>..<HASH> 100644
--- a/activemodel/lib/active_model/secure_password.rb
+++ b/activemodel/lib/active_model/secure_password.rb
@@ -3,6 +3,7 @@ module ActiveModel
     extend ActiveSupport::Concern
 
     class << self; attr_accessor :min_cost; end
+    self.min_cost = false
 
     module ClassMethods
       # Adds methods to set and authenticate against a BCrypt password.
@@ -13,8 +14,8 @@ module ActiveModel
       # you wish to turn off validations, pass <tt>validations: false</tt> as an
       # argument. You can add more validations by hand if need be.
       #
-      # If you don't need the confirmation validation, just don't set any 
-      # value to the password_confirmation attribute and the the validation 
+      # If you don't need the confirmation validation, just don't set any
+      # value to the password_confirmation attribute and the the validation
       # will not be triggered.
       #
       # You need to add bcrypt-ruby (~> 3.0.0) to Gemfile to use #has_secure_password:
Initialize #min_cost to avoid warning in Ruby <I>