diff --git a/h5bp/ssl/policy_modern.conf b/h5bp/ssl/policy_modern.conf
index 92c9a59..0a7768e 100644
--- a/h5bp/ssl/policy_modern.conf
+++ b/h5bp/ssl/policy_modern.conf
@@ -14,4 +14,5 @@
 
 ssl_protocols TLSv1.2;
 ssl_ciphers EECDH+CHACHA20:EECDH+AES;
+ssl_ecdh_curve X25519:prime256v1:secp384r1:secp521r1;
 ssl_prefer_server_ciphers on;