diff --git a/bin/ovpn_genconfig b/bin/ovpn_genconfig
index b78953d..8df36d0 100755
--- a/bin/ovpn_genconfig
+++ b/bin/ovpn_genconfig
@@ -293,8 +293,8 @@ EOF
 [ -n "$OVPN_CIPHER" ] && echo "cipher $OVPN_CIPHER" >> "$conf"
 [ -n "$OVPN_AUTH" ] && echo "auth $OVPN_AUTH" >> "$conf"
 
-[ -n "$OVPN_CLIENT_TO_CLIENT" ] && echo "client-to-client" >> "$conf"
-[ -n "$OVPN_COMP_LZO" ] && echo "comp-lzo" >> "$conf"
+[ -n "${OVPN_CLIENT_TO_CLIENT:-}" ] && echo "client-to-client" >> "$conf"
+[ -n "${OVPN_COMP_LZO:-}" ] && echo "comp-lzo" >> "$conf"
 
 [ -n "${OVPN_FRAGMENT:-}" ] && echo "fragment $OVPN_FRAGMENT" >> "$conf"