diff --git a/test/integration/api_test/projects_test.rb b/test/integration/api_test/projects_test.rb
--- a/test/integration/api_test/projects_test.rb
+++ b/test/integration/api_test/projects_test.rb
@@ -158,6 +158,48 @@ class Redmine::ApiTest::ProjectsTest < R
     assert_select 'project id', :text => project.id.to_s
   end
 
+  def test_issue_27584
+    with_settings :default_projects_modules => [] do
+      assert_difference('Project.count') do
+        post '/projects.xml',
+          :params => {:project => {:name => 'API test', :identifier => 'api-test'}},
+          :headers => credentials('admin')
+      end
+    end
+
+    project = Project.order('id DESC').first
+    assert_equal 'API test', project.name
+    assert_equal 'api-test', project.identifier
+    assert_equal [], project.enabled_module_names.sort
+    assert_equal Tracker.all.size, project.trackers.size
+
+    assert_response :created
+    assert_equal 'application/xml', @response.content_type
+    assert_select 'project id', :text => project.id.to_s
+
+    project.reload
+
+    assert_no_difference 'Project.count' do
+      put "/projects/#{project.id}.xml",
+        :params => {:project => {:enabled_module_names => ['issue_tracking']}},
+        :headers => credentials('admin')
+    end
+    assert_response :ok
+    assert_equal '', @response.body
+    project.reload
+    assert_equal ['issue_tracking'], project.enabled_module_names.sort
+
+    assert_no_difference 'Project.count' do
+      put "/projects/#{project.id}.xml",
+        :params => {:project => {:enabled_module_names => ['news']}},
+        :headers => credentials('admin')
+    end
+    assert_response :ok
+    assert_equal '', @response.body
+    project.reload
+    assert_equal ['news'], project.enabled_module_names.sort
+  end
+
   test "POST /projects.xml should accept enabled_module_names attribute" do
     assert_difference('Project.count') do
       post '/projects.xml',