diff --git a/py/parse.c b/py/parse.c
index 5920828fe9..397d46d9f0 100644
--- a/py/parse.c
+++ b/py/parse.c
@@ -1010,9 +1010,10 @@ mp_parse_tree_t mp_parse(mp_lexer_t *lex, mp_parse_input_kind_t input_kind) {
 
     // truncate final chunk and link into chain of chunks
     if (parser.cur_chunk != NULL) {
-        (void)m_renew(byte, parser.cur_chunk,
+        (void)m_renew_maybe(byte, parser.cur_chunk,
             sizeof(mp_parse_chunk_t) + parser.cur_chunk->alloc,
-            sizeof(mp_parse_chunk_t) + parser.cur_chunk->union_.used);
+            sizeof(mp_parse_chunk_t) + parser.cur_chunk->union_.used,
+            false);
         parser.cur_chunk->alloc = parser.cur_chunk->union_.used;
         parser.cur_chunk->union_.next = parser.tree.chunk;
         parser.tree.chunk = parser.cur_chunk;
diff --git a/py/qstr.c b/py/qstr.c
index 28df06ca3d..5aa1610648 100644
--- a/py/qstr.c
+++ b/py/qstr.c
@@ -199,7 +199,7 @@ qstr qstr_from_strn(const char *str, size_t len) {
             byte *new_p = m_renew_maybe(byte, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_alloc) + n_bytes, false);
             if (new_p == NULL) {
                 // could not grow existing memory; shrink it to fit previous
-                (void)m_renew(byte, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_used));
+                (void)m_renew_maybe(byte, MP_STATE_VM(qstr_last_chunk), MP_STATE_VM(qstr_last_alloc), MP_STATE_VM(qstr_last_used), false);
                 MP_STATE_VM(qstr_last_chunk) = NULL;
             } else {
                 // could grow existing memory