diff --git a/app/controllers/attachments_controller.rb b/app/controllers/attachments_controller.rb
index ea45397..d7637aa 100644
--- a/app/controllers/attachments_controller.rb
+++ b/app/controllers/attachments_controller.rb
@@ -22,7 +22,7 @@ class AttachmentsController < ApplicationController
   before_filter :delete_authorize, :only => :destroy
   before_filter :authorize_global, :only => :upload
 
-  accept_api_auth :show, :download, :thumbnail, :upload, :destroy
+  accept_api_auth :show, :download, :thumbnail, :upload, :update, :destroy
 
   def show
     respond_to do |format|
@@ -109,11 +109,17 @@ class AttachmentsController < ApplicationController
   def update
     if params[:attachments].is_a?(Hash)
       if Attachment.update_attachments(@attachments, params[:attachments])
-        redirect_back_or_default home_path
-        return
+        respond_to do |format|
+          format.html { redirect_back_or_default home_path }
+          format.api { render_api_ok }
+        end
+      return
       end
     end
-    render :action => 'edit'
+    respond_to do |format|
+      format.html { render :action => 'edit' }
+      format.api { render_validation_errors(@attachments) }
+    end
   end
 
   def destroy
diff --git a/test/integration/api_test/attachments_test.rb b/test/integration/api_test/attachments_test.rb
index 640a782..f551a60 100644
--- a/test/integration/api_test/attachments_test.rb
+++ b/test/integration/api_test/attachments_test.rb
@@ -99,6 +99,46 @@ class Redmine::ApiTest::AttachmentsTest < Redmine::ApiTest::Base
     assert_nil Attachment.find_by_id(7)
   end
 
+  test "PATCH /attachments/issues/:id.json should return ok and updated Attachment" do
+    token = json_upload('File content 1', credentials('jsmith'))
+   
+    payload = <<-JSON
+{
+  "issue": {
+    "project_id": "1",
+    "tracker_id": "1",
+    "subject": "Issue with attachment",
+    "uploads": [
+      {"token": "#{token}", "filename": "test1.txt", "description": "test1"}
+    ]
+  }
+}
+JSON
+
+    assert_difference 'Issue.count' do
+      post '/issues.json', payload, {"CONTENT_TYPE" => 'application/json'}.merge(credentials('jsmith'))
+      assert_response :created
+    end
+	
+    issue = Issue.order('id DESC').first
+    assert_equal 1, issue.attachments.count
+	
+	attachment = issue.attachments.first
+    attachment.filename = "test1_updated.txt"
+	attachment.description = "test1_updated"
+	
+	data = {:attachments => {attachment.id => {:filename => attachment.filename, :description => attachment.description}}}
+    patch "/attachments/issues/#{issue.id}.json", data, credentials('jsmith')
+	assert_response :ok
+	
+    updatedIssue = Issue.find(issue.id)
+	updatedAttachment = updatedIssue.attachments.first;
+	
+    assert_equal "Issue with attachment", updatedIssue.subject
+	assert_equal "test1_updated.txt", updatedAttachment.filename
+	assert_equal "test1_updated", updatedAttachment.description
+  end
+  
   test "POST /uploads.xml should return the token" do
     set_tmp_attachments_directory
     assert_difference 'Attachment.count' do