diff --git a/nixos/modules/services/misc/zoneminder.nix b/nixos/modules/services/misc/zoneminder.nix
index 6e83d47df1c..bf38b9ad7a2 100644
--- a/nixos/modules/services/misc/zoneminder.nix
+++ b/nixos/modules/services/misc/zoneminder.nix
@@ -200,7 +200,10 @@ in {
       "zoneminder/80-nixos.conf".source    = configFile;
     };
 
-    networking.firewall.allowedTCPPorts = lib.mkIf cfg.openFirewall [ cfg.port ];
+    networking.firewall.allowedTCPPorts = lib.mkIf cfg.openFirewall [
+      cfg.port
+      6802 # zmtrigger
+    ];
 
     services = {
       fcgiwrap = lib.mkIf useNginx {
diff --git a/pkgs/servers/zoneminder/default.nix b/pkgs/servers/zoneminder/default.nix
index 5a052df9e0a..996bd6a8fb6 100644
--- a/pkgs/servers/zoneminder/default.nix
+++ b/pkgs/servers/zoneminder/default.nix
@@ -146,7 +146,7 @@ in stdenv.mkDerivation rec {
     # build-time dependencies
     DateManip DBI DBDmysql LWP SysMmap
     # run-time dependencies not checked at build-time
-    ClassStdFast DataDump JSONMaybeXS LWPProtocolHttps NumberBytesHuman SysCPU SysMemInfo TimeDate
+    ClassStdFast DataDump DeviceSerialPort JSONMaybeXS LWPProtocolHttps NumberBytesHuman SysCPU SysMemInfo TimeDate
   ]);
 
   nativeBuildInputs = [ cmake makeWrapper pkgconfig ];
diff --git a/pkgs/top-level/perl-packages.nix b/pkgs/top-level/perl-packages.nix
index cd9d4936491..1d0b4b2e190 100644
--- a/pkgs/top-level/perl-packages.nix
+++ b/pkgs/top-level/perl-packages.nix
@@ -15004,6 +15004,18 @@ let
     };
   };
 
+  DeviceSerialPort = buildPerlPackage rec {
+    name = "Device-SerialPort-1.04";
+    src = fetchurl {
+      url = "mirror://cpan/authors/id/C/CO/COOK/${name}.tar.gz";
+      sha256 = "1mz9a2qzkz6fbz76wcwmp48h6ckjxpcazb70q03acklvndy5d4nk";
+    };
+    meta = with stdenv.lib; {
+      description = "Linux/POSIX emulation of Win32::SerialPort functions.";
+      license = with licenses; [ artistic1 gpl1Plus ];
+    };
+  };
+
   ServerStarter = buildPerlModule {
     pname = "Server-Starter";
     version = "0.34";