diff --git a/nixos/modules/misc/ids.nix b/nixos/modules/misc/ids.nix
index 79c1c1e000ca..31de680514e6 100644
--- a/nixos/modules/misc/ids.nix
+++ b/nixos/modules/misc/ids.nix
@@ -244,6 +244,7 @@
       teamspeak = 124;
       influxdb = 125;
       nsd = 126;
+      firebird = 127;
       znc = 128;
 
       # When adding a gid, make sure it doesn't match an existing uid. And don't use gids above 399!
diff --git a/nixos/modules/services/databases/firebird.nix b/nixos/modules/services/databases/firebird.nix
index 83dd4951170a..c874b218a5e7 100644
--- a/nixos/modules/services/databases/firebird.nix
+++ b/nixos/modules/services/databases/firebird.nix
@@ -159,5 +159,7 @@ in
       uid = config.ids.uids.firebird;
     };
 
+    users.extraGroups.firebird.gid = config.ids.gids.firebird;
+
   };
 }