diff --git a/test/mitmproxy/proxy/test_mode_specs.py b/test/mitmproxy/proxy/test_mode_specs.py
index a3882d803..8f3fdb370 100644
--- a/test/mitmproxy/proxy/test_mode_specs.py
+++ b/test/mitmproxy/proxy/test_mode_specs.py
@@ -54,7 +54,7 @@ def test_parse_specific_modes():
     assert ProxyMode.parse("socks5")
     assert ProxyMode.parse("dns").resolve_local
     assert ProxyMode.parse("dns:reverse:8.8.8.8")
-    assert ProxyMode.parse("dtls:reverse:127.0.0.1:0")
+    assert ProxyMode.parse("dtls:reverse:127.0.0.1:8004")
 
     with pytest.raises(ValueError, match="invalid port"):
         ProxyMode.parse("regular@invalid-port")