diff --git a/libmproxy/proxy/config.py b/libmproxy/proxy/config.py
index 0b45d83ee..c7b513112 100644
--- a/libmproxy/proxy/config.py
+++ b/libmproxy/proxy/config.py
@@ -56,7 +56,7 @@ class ProxyConfig:
             tcp_hosts=tuple(),
             http2=False,
             rawtcp=False,
-            ciphers_client=None,
+            ciphers_client=DEFAULT_CLIENT_CIPHERS,
             ciphers_server=None,
             certs=tuple(),
             ssl_version_client="secure",