diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 934f772..6b0df56 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -517,7 +517,7 @@
 P_SRV="$P_SRV server_addr=127.0.0.1 server_port=$SRV_PORT"
 P_CLI="$P_CLI server_addr=127.0.0.1 server_port=+SRV_PORT"
 P_PXY="$P_PXY server_addr=127.0.0.1 server_port=$SRV_PORT listen_addr=127.0.0.1 listen_port=$PXY_PORT"
-O_SRV="$O_SRV -accept $SRV_PORT"
+O_SRV="$O_SRV -accept $SRV_PORT -dhparam data_files/dhparams.pem"
 O_CLI="$O_CLI -connect localhost:+SRV_PORT"
 G_SRV="$G_SRV -p $SRV_PORT"
 G_CLI="$G_CLI -p +SRV_PORT localhost"