diff --git a/README.md b/README.md
index eef74b27..2c9c560c 100644
--- a/README.md
+++ b/README.md
@@ -108,8 +108,8 @@ libwps-tools gzip unrtf catdvi djview djview3 uuid uuid-dev xz-utils libemail-ou
 
 On CentOS use:
 ```
-sudo yum install xapian-binding libxapian-dev xpdf poppler-utils antiword unzip catdoc libwpd-tools libwps-tools gzip \
-unrtf catdvi djview djview3 uuid uuid-dev xz libemail-outlook-message-perl
+sudo yum install xapian-core xapian-bindings-ruby libxapian-dev xpdf poppler-utils antiword unzip catdoc libwpd-tools \
+libwps-tools gzip unrtf catdvi djview djview3 uuid uuid-dev xz libemail-outlook-message-perl
 ```
 
 Usage
diff --git a/lib/redmine_dmsf/webdav/project_resource.rb b/lib/redmine_dmsf/webdav/project_resource.rb
index a14ce40e..f575ba8e 100644
--- a/lib/redmine_dmsf/webdav/project_resource.rb
+++ b/lib/redmine_dmsf/webdav/project_resource.rb
@@ -98,6 +98,11 @@ module RedmineDmsf
         OK
       end
 
+      def make_collection
+        # It's not allowed to create folders on project level
+        MethodNotAllowed
+      end
+
       def folder
         nil
       end
diff --git a/test/integration/webdav/dmsf_webdav_mkcol_test.rb b/test/integration/webdav/dmsf_webdav_mkcol_test.rb
index 0e38f155..3283db2b 100644
--- a/test/integration/webdav/dmsf_webdav_mkcol_test.rb
+++ b/test/integration/webdav/dmsf_webdav_mkcol_test.rb
@@ -54,7 +54,7 @@ class DmsfWebdavMkcolTest < RedmineDmsf::Test::IntegrationTest
 
   def test_mkcol_fails_to_create_folder_at_root_level
     xml_http_request  :mkcol, '/dmsf/webdav/test1', nil, @admin
-    assert_response :error # 501 - Not Implemented at this level
+    assert_response 405 # 405 - Method Not Allowed
   end
 
   def test_should_not_succeed_on_a_non_existant_project