diff --git a/unix/modos.c b/unix/modos.c
index 5c81caa5cbc48aeeb509bf00997e549db221f235..a6be4bfff0c29dce5a8bd8f0cb558b7424696f2f 100644
--- a/unix/modos.c
+++ b/unix/modos.c
@@ -44,7 +44,8 @@
 
 STATIC mp_obj_t mod_os_stat(mp_obj_t path_in) {
     struct stat sb;
-    const char *path = mp_obj_str_get_str(path_in);
+    uint len;
+    const char *path = mp_obj_str_get_data(path_in, &len);
 
     int res = stat(path, &sb);
     RAISE_ERRNO(res, errno);