diff --git a/include/xbps_api.h b/include/xbps_api.h
index 735a36c4..aa814799 100644
--- a/include/xbps_api.h
+++ b/include/xbps_api.h
@@ -875,16 +875,9 @@ void xbps_repository_pool_release(void);
 int xbps_repository_sync_pkg_index(const char *uri);
 
 /**
- * Returns a malloc(3)ed string with the local directory name for
- * the package cache directory pointing to a remote URI repository.
- *
- * @note The caller is responsible to free(3) the returned buffer,
- * @param[in] uri URI to a remote repository.
- *
- * @return A buffer with the transformed string, NULL otherwise and
- * errno is set appropiately.
+ * @private
  */
-char *xbps_get_remote_repo_string(const char *uri);
+char HIDDEN *xbps_get_remote_repo_string(const char *uri);
 
 /*@}*/
 
diff --git a/lib/repository_sync_index.c b/lib/repository_sync_index.c
index d7a2cb8e..a9af4c3b 100644
--- a/lib/repository_sync_index.c
+++ b/lib/repository_sync_index.c
@@ -37,9 +37,12 @@
  * @file lib/repository_sync_index.c
  * @brief Repository package index synchronization routines
  * @defgroup reposync Repository package index synchronization functions
+ *
+ * Functions to manipulate repository package index plist file
+ * synchronizations.
  */
 
-char *
+char HIDDEN *
 xbps_get_remote_repo_string(const char *uri)
 {
 	struct url *url;