1 files changed, 17 insertions, 6 deletions
diff --git a/activemodel/lib/active_model/translation.rb b/activemodel/lib/active_model/translation.rb
index 6d64c81b5f..6f0ca92e2a 100644
--- a/activemodel/lib/active_model/translation.rb
+++ b/activemodel/lib/active_model/translation.rb
@@ -1,5 +1,3 @@
-require 'active_support/core_ext/hash/reverse_merge'
-
 module ActiveModel
 
   # == Active Model Translation
@@ -43,15 +41,28 @@ module ActiveModel
     #
     # Specify +options+ with additional translating options.
     def human_attribute_name(attribute, options = {})
-      defaults = lookup_ancestors.map do |klass|
-        :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
+      options   = { :count => 1 }.merge!(options)
+      parts     = attribute.to_s.split(".", 2)
+      attribute = parts.pop
+      namespace = parts.pop
+      attributes_scope = "#{self.i18n_scope}.attributes"
+
+      if namespace
+        defaults = lookup_ancestors.map do |klass|
+          :"#{attributes_scope}.#{klass.model_name.i18n_key}/#{namespace}.#{attribute}"
+        end
+        defaults << :"#{attributes_scope}.#{namespace}.#{attribute}"
+      else
+        defaults = lookup_ancestors.map do |klass|
+          :"#{attributes_scope}.#{klass.model_name.i18n_key}.#{attribute}"
+        end
       end
 
       defaults << :"attributes.#{attribute}"
       defaults << options.delete(:default) if options[:default]
-      defaults << attribute.to_s.humanize
+      defaults << attribute.humanize
 
-      options.reverse_merge! :count => 1, :default => defaults
+      options[:default] = defaults
       I18n.translate(defaults.shift, options)
     end
   end