diff --git a/lib/redmine_dmsf/webdav/custom_middleware.rb b/lib/redmine_dmsf/webdav/custom_middleware.rb
index 938986cd..be81c422 100644
--- a/lib/redmine_dmsf/webdav/custom_middleware.rb
+++ b/lib/redmine_dmsf/webdav/custom_middleware.rb
@@ -60,7 +60,7 @@ module RedmineDmsf
           # plain HTTP is going on.
           if (env['REQUEST_METHOD'].present? && ('OPTIONS'.casecmp(env['REQUEST_METHOD']) == 0)) &&
               (env['PATH_INFO'].present? && env['PATH_INFO'].start_with?('/dmsf')) # *
-            [ '200', { :Allow => 'OPTIONS,HEAD,GET,PUT,POST,DELETE' }, [''] ]
+            [ '200', { 'Allow' => 'OPTIONS,HEAD,GET,PUT,POST,DELETE' }, [''] ]
             # * This's a new condition in order to not process WebDAV request which doesn't belong to DMS. But, it might
             # case problems when acessing /dmsf and consequently /
           else
diff --git a/lib/redmine_dmsf/webdav/dmsf_resource.rb b/lib/redmine_dmsf/webdav/dmsf_resource.rb
index 331bf72a..ba38136d 100644
--- a/lib/redmine_dmsf/webdav/dmsf_resource.rb
+++ b/lib/redmine_dmsf/webdav/dmsf_resource.rb
@@ -239,7 +239,7 @@ module RedmineDmsf
           end
 
           # At the moment we don't support cross project destinations
-          return MethodNotImplemented unless (project.id == resource.project.id)
+          return NotImplemented unless (project.id == resource.project.id)
           raise Forbidden unless User.current.admin? || User.current.allowed_to?(:folder_manipulation, project)
           raise Forbidden unless DmsfFolder.permissions?(folder, false)