diff --git a/py/objstr.c b/py/objstr.c
index 84f872f..4f032d3 100644
--- a/py/objstr.c
+++ b/py/objstr.c
@@ -518,12 +518,12 @@
                 }
                 s++;
             }
-            mp_uint_t len = s - start;
+            mp_uint_t sub_len = s - start;
             if (MP_LIKELY(!(len == 0 && s == top && (type && SPLITLINES)))) {
                 if (start + len != top && (type & KEEP)) {
-                    len++;
+                    sub_len++;
                 }
-                mp_obj_list_append(res, mp_obj_new_str_of_type(self_type, start, len));
+                mp_obj_list_append(res, mp_obj_new_str_of_type(self_type, start, sub_len));
             }
             if (s >= top) {
                 break;