diff --git a/lib/picotls.c b/lib/picotls.c
index a7ed1b7..03b6884 100644
--- a/lib/picotls.c
+++ b/lib/picotls.c
@@ -2572,7 +2572,7 @@
             ptls__key_schedule_update_hash(tls->key_schedule, message.base, message.len, 0);
             if ((ret = ech_calc_confirmation(tls->key_schedule, confirm_hash_expected, tls->client_random.inner, label)) != 0)
                 goto Exit;
-            if (memcmp(confirm_hash_delivered, confirm_hash_expected, sizeof(confirm_hash_delivered)) == 0)
+            if (ptls_mem_equal(confirm_hash_delivered, confirm_hash_expected, sizeof(confirm_hash_delivered)))
                 goto Exit;
             memcpy(message.base + confirm_hash_off, confirm_hash_delivered, sizeof(confirm_hash_delivered));
         }