diff --git a/lib/redmine_dmsf/webdav/base_resource.rb b/lib/redmine_dmsf/webdav/base_resource.rb
index 00b78e58..c7fea5e6 100644
--- a/lib/redmine_dmsf/webdav/base_resource.rb
+++ b/lib/redmine_dmsf/webdav/base_resource.rb
@@ -128,7 +128,7 @@ module RedmineDmsf
                   prj = Project.visible.find_by(id: $1)
                   if prj
                     # Check again whether it's really the project and not a folder with a number as a suffix
-                    prj = nil unless pinfo.first =~ /^#{prj.name}/
+                    prj = nil unless pinfo.first =~ /^#{DmsfFolder::get_valid_title(prj.name)}/
                   end
                 end
               else
@@ -156,7 +156,7 @@ module RedmineDmsf
                 prj = Project.visible.find_by(id: $1)
                 if prj
                   # Check again whether it's really the project and not a folder with a number as a suffix
-                  prj = nil unless pinfo.first =~ /^#{prj.name}/
+                  prj = nil unless pinfo.first =~ /^#{DmsfFolder::get_valid_title(prj.name)}/
                 end
               end
             else
diff --git a/lib/redmine_dmsf/webdav/dmsf_resource.rb b/lib/redmine_dmsf/webdav/dmsf_resource.rb
index 86450d95..a5d50afd 100644
--- a/lib/redmine_dmsf/webdav/dmsf_resource.rb
+++ b/lib/redmine_dmsf/webdav/dmsf_resource.rb
@@ -114,7 +114,7 @@ module RedmineDmsf
               @subproject = Project.visible.find_by(id: $1, parent_id: parent_project&.id)
               if @subproject
                 # Check again whether it's really the project and not a folder with a number as a suffix
-                @subproject = nil unless basename =~ /^#{@subproject.name}/
+                @subproject = nil unless basename =~ /^#{DmsfFolder::get_valid_title(@subproject.name)}/
               end
             end
           else