diff --git a/nixos/modules/services/databases/mysql.nix b/nixos/modules/services/databases/mysql.nix
index 2d8d613ed88e..b801b5cce635 100644
--- a/nixos/modules/services/databases/mysql.nix
+++ b/nixos/modules/services/databases/mysql.nix
@@ -48,7 +48,7 @@ in
       };
 
       port = mkOption {
-        type = types.int;
+        type = types.port;
         default = 3306;
         description = "Port of MySQL.";
       };