3 files changed, 4 insertions, 4 deletions
diff --git a/activemodel/lib/active_model/dirty.rb b/activemodel/lib/active_model/dirty.rb
index ecb7a9e9b1..6e67cd2285 100644
--- a/activemodel/lib/active_model/dirty.rb
+++ b/activemodel/lib/active_model/dirty.rb
@@ -119,7 +119,7 @@ module ActiveModel
     #   person.name = 'bob'
     #   person.changes # => { "name" => ["bill", "bob"] }
     def changes
-      HashWithIndifferentAccess[changed.map { |attr| [attr, attribute_change(attr)] }]
+      ActiveSupport::HashWithIndifferentAccess[changed.map { |attr| [attr, attribute_change(attr)] }]
     end
 
     # Returns a hash of attributes that were changed before the model was saved.
diff --git a/activemodel/lib/active_model/validations/clusivity.rb b/activemodel/lib/active_model/validations/clusivity.rb
index 3d7067fbcb..49df98d6c1 100644
--- a/activemodel/lib/active_model/validations/clusivity.rb
+++ b/activemodel/lib/active_model/validations/clusivity.rb
@@ -3,7 +3,7 @@ require 'active_support/core_ext/range'
 module ActiveModel
   module Validations
     module Clusivity #:nodoc:
-      ERROR_MESSAGE = "An object with the method #include? or a proc, lambda or symbol is required, " <<
+      ERROR_MESSAGE = "An object with the method #include? or a proc, lambda or symbol is required, " \
                       "and must be supplied as the :in (or :within) option of the configuration hash"
 
       def check_validity!
diff --git a/activemodel/lib/active_model/validations/numericality.rb b/activemodel/lib/active_model/validations/numericality.rb
index 744c196d30..085532c35b 100644
--- a/activemodel/lib/active_model/validations/numericality.rb
+++ b/activemodel/lib/active_model/validations/numericality.rb
@@ -17,9 +17,9 @@ module ActiveModel
       end
 
       def validate_each(record, attr_name, value)
-        before_type_cast = "#{attr_name}_before_type_cast"
+        before_type_cast = :"#{attr_name}_before_type_cast"
 
-        raw_value = record.send(before_type_cast) if record.respond_to?(before_type_cast.to_sym)
+        raw_value = record.send(before_type_cast) if record.respond_to?(before_type_cast)
         raw_value ||= value
 
         return if options[:allow_nil] && raw_value.nil?