2 files changed, 16 insertions, 2 deletions
diff --git a/activemodel/lib/active_model/translation.rb b/activemodel/lib/active_model/translation.rb
index 6d64c81b5f..d776fe0ce6 100644
--- a/activemodel/lib/active_model/translation.rb
+++ b/activemodel/lib/active_model/translation.rb
@@ -43,8 +43,12 @@ 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}"
+      defaults = []
+      lookup_ancestors.each do |klass|
+        if attribute.match(/\./)
+          defaults << :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute.gsub(/\./, '/')}"
+        end
+        defaults << :"#{self.i18n_scope}.attributes.#{klass.model_name.i18n_key}.#{attribute}"
       end
 
       defaults << :"attributes.#{attribute}"
diff --git a/activemodel/test/cases/translation_test.rb b/activemodel/test/cases/translation_test.rb
index 1b1d972d5c..c3d60d6c8b 100644
--- a/activemodel/test/cases/translation_test.rb
+++ b/activemodel/test/cases/translation_test.rb
@@ -56,6 +56,16 @@ class ActiveModelI18nTests < ActiveModel::TestCase
     assert_equal 'person gender attribute', Person::Gender.human_attribute_name('attribute')
   end
 
+  def test_translated_nested_model_attributes
+    I18n.backend.store_translations 'en', :activemodel => {:attributes => {:person => {:"addresses/street" => 'Street'}}}
+    assert_equal 'Street', Person.human_attribute_name('addresses.street')
+  end
+
+  def test_translated_nested_model_attributes_with_deprecated_lookup_style
+    I18n.backend.store_translations 'en', :activemodel => {:attributes => {:person => {:addresses => {:street => 'Street'}}}}
+    assert_equal 'Street', Person.human_attribute_name('addresses.street')
+  end
+
   def test_translated_model_names
     I18n.backend.store_translations 'en', :activemodel => {:models => {:person => 'person model'} }
     assert_equal 'person model', Person.model_name.human