diff --git a/modules/cloonar-assistant/default.nix b/modules/cloonar-assistant/default.nix
index 2ce327c..fea0992 100644
--- a/modules/cloonar-assistant/default.nix
+++ b/modules/cloonar-assistant/default.nix
@@ -149,6 +149,7 @@ in {
       custom-rules = {
         input = lib.mkOption {
           type = with types; nullOr lines;
+          default = '''';
           example = ''
             iifname "lan" udp dport 22 counter accept comment "Wireguard traffic"
             iifname "lan" udp dport 80 counter accept comment "Wireguard traffic"
@@ -157,6 +158,7 @@ in {
         };
         forward = lib.mkOption {
           type = with types; nullOr lines;
+          default = '''';
           example = ''
             iifname "lan" oifname "server" tcp dport { 22 } counter accept
             iifname "lan" oifname "server" tcp dport { 80 } counter accept
@@ -165,6 +167,7 @@ in {
         };
         prerouting = lib.mkOption {
           type = with types; nullOr lines;
+          default = '''';
           example = ''
             iifname "server" ip daddr 10.0.96.255 udp dport { 9 } dnat to 10.0.96.255
           '';
@@ -172,6 +175,7 @@ in {
         };
         postrouting = lib.mkOption {
           type = with types; nullOr lines;
+          default = '''';
           example = ''
             oifname { "wan" } masquerade
           '';