diff --git a/docker-entrypoint.sh b/docker-entrypoint.sh
index c91b1c13..0d34ab2d 100755
--- a/docker-entrypoint.sh
+++ b/docker-entrypoint.sh
@@ -2,7 +2,11 @@
 set -e
 
 if [ "${USE_PROXY}" == "1" ]; then
-  exec tmate-ssh-server -p 2200 -k ${SSH_KEYS_PATH} -h ${SSH_HOSTNAME} -x localhost
-else
-  exec tmate-ssh-server -p 2200 -k ${SSH_KEYS_PATH} -h ${SSH_HOSTNAME}
+  set -- -x localhost "$@"
 fi
+
+if [ ! -z "${HOSTNAME}" ]; then
+  set -- -h "${HOSTNAME}" "$@"
+fi
+
+exec tmate-ssh-server -p 2200 -k ${SSH_KEYS_PATH} "$@"