Labels only available for translation in the database when adding a contact type

In a non-english language, if you add a contact type Testtype, the associated menu-item isn't available for translation.
The string 'New Testtype' is inserted in the civicrm_navigation table, the only way to translate it is to use the "Word Replacements" tool.

Since I work in a single language installation and I insert an already translated type, I wouldn't expect any translation problem...