diff --git a/src/lib/eina/eina_ustringshare.h b/src/lib/eina/eina_ustringshare.h
index 6a6d7c6bad..073b74cd4b 100644
--- a/src/lib/eina/eina_ustringshare.h
+++ b/src/lib/eina/eina_ustringshare.h
@@ -168,6 +168,7 @@ EAPI void                eina_ustringshare_del(const Eina_Unicode *str);
  *
  * @param str The shared string to know the length. It is safe to
  *        give @c NULL, in that case @c -1 is returned.
+ * @return The length of a shared string.
  *
  * This function is a cheap way to known the length of a shared
  * string.