diff --git a/app/controllers/repositories_controller.rb b/app/controllers/repositories_controller.rb
index 9be7878ce..d6a13daf2 100644
--- a/app/controllers/repositories_controller.rb
+++ b/app/controllers/repositories_controller.rb
@@ -160,7 +160,15 @@ class RepositoriesController < ApplicationController
       # Force the download
       send_opt = {:filename => filename_for_content_disposition(@path.split('/').last)}
       send_type = Redmine::MimeType.of(@path)
-      send_opt[:type] = send_type.to_s if send_type
+      case send_type
+      when nil
+        # No MIME type detected. Let Rails use the default type.
+      when 'application/javascript'
+        # Avoid ActionController::InvalidCrossOriginRequest exception by setting non-JS content type
+        send_opt[:type] = 'text/plain'
+      else
+        send_opt[:type] = send_type
+      end
       send_opt[:disposition] = disposition(@path)
       send_data @repository.cat(@path, @rev), send_opt
     else
diff --git a/test/functional/repositories_subversion_controller_test.rb b/test/functional/repositories_subversion_controller_test.rb
index 7de85a78d..0a430317f 100644
--- a/test/functional/repositories_subversion_controller_test.rb
+++ b/test/functional/repositories_subversion_controller_test.rb
@@ -358,6 +358,27 @@ class RepositoriesSubversionControllerTest < Redmine::RepositoryControllerTest
       assert_equal "attachment; filename=\"helloworld.c\"; filename*=UTF-8''helloworld.c", @response.headers['Content-Disposition']
     end
 
+    def test_entry_should_return_text_plain_for_js_files
+      # JavaScript files should be served as 'text/plain' instead of
+      # 'application/javascript' to avoid
+      # ActionController::InvalidCrossOriginRequest exception
+      assert_equal 0, @repository.changesets.count
+      @repository.fetch_changesets
+      @project.reload
+      assert_equal NUM_REV, @repository.changesets.count
+      get(
+        :raw,
+        :params => {
+          :id => PRJ_ID,
+          :repository_id => @repository.id,
+          :path => repository_path_hash(['subversion_test', 'foo.js'])[:param]
+        }
+      )
+      assert_response :success
+      assert_equal 'text/plain', @response.media_type
+      assert_match /attachment/, @response.headers['Content-Disposition']
+    end
+
     def test_directory_entry
       assert_equal 0, @repository.changesets.count
       @repository.fetch_changesets