diff --git a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
index c2cc42b708ff..5598709d59ae 100644
--- a/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
+++ b/nixos/doc/manual/from_md/release-notes/rl-2205.section.xml
@@ -1043,6 +1043,14 @@
           <literal>admin</literal> and <literal>password</literal>.
         </para>
       </listitem>
+      <listitem>
+        <para>
+          The <literal>taskserver</literal> module no longer implicitly
+          opens ports in the firewall configuration. This is now
+          controlled through the option
+          <literal>services.taskserver.openFirewall</literal>.
+        </para>
+      </listitem>
       <listitem>
         <para>
           The <literal>autorestic</literal> package has been upgraded
diff --git a/nixos/doc/manual/release-notes/rl-2205.section.md b/nixos/doc/manual/release-notes/rl-2205.section.md
index 530a73941391..7373a5f4875d 100644
--- a/nixos/doc/manual/release-notes/rl-2205.section.md
+++ b/nixos/doc/manual/release-notes/rl-2205.section.md
@@ -443,6 +443,10 @@ In addition to numerous new and upgraded packages, this release has the followin
 
 - `services.miniflux.adminCredentialFiles` is now required, instead of defaulting to `admin` and `password`.
 
+- The `taskserver` module no longer implicitly opens ports in the firewall
+  configuration. This is now controlled through the option
+  `services.taskserver.openFirewall`.
+
 - The `autorestic` package has been upgraded from 1.3.0 to 1.5.0 which introduces breaking changes in config file, check [their migration guide](https://autorestic.vercel.app/migration/1.4_1.5) for more details.
 
 - For `pkgs.python3.pkgs.ipython`, its direct dependency `pkgs.python3.pkgs.matplotlib-inline`
diff --git a/nixos/modules/services/misc/taskserver/default.nix b/nixos/modules/services/misc/taskserver/default.nix
index ff63c41e193c..e20804929981 100644
--- a/nixos/modules/services/misc/taskserver/default.nix
+++ b/nixos/modules/services/misc/taskserver/default.nix
@@ -106,7 +106,7 @@ let
 
   certtool = "${pkgs.gnutls.bin}/bin/certtool";
 
-  nixos-taskserver = with pkgs.python2.pkgs; buildPythonApplication {
+  nixos-taskserver = with pkgs.python3.pkgs; buildPythonApplication {
     name = "nixos-taskserver";
 
     src = pkgs.runCommand "nixos-taskserver-src" { preferLocalBuild = true; } ''
@@ -277,10 +277,6 @@ in {
         example = "::";
         description = ''
           The address (IPv4, IPv6 or DNS) to listen on.
-
-          If the value is something else than <literal>localhost</literal> the
-          port defined by <option>listenPort</option> is automatically added to
-          <option>networking.firewall.allowedTCPPorts</option>.
         '';
       };
 
@@ -292,6 +288,14 @@ in {
         '';
       };
 
+      openFirewall = mkOption {
+        type = types.bool;
+        default = false;
+        description = ''
+          Whether to open the firewall for the specified Taskserver port.
+        '';
+      };
+
       fqdn = mkOption {
         type = types.str;
         default = "localhost";
@@ -560,7 +564,7 @@ in {
         '';
       };
     })
-    (mkIf (cfg.enable && cfg.listenHost != "localhost") {
+    (mkIf (cfg.enable && cfg.openFirewall) {
       networking.firewall.allowedTCPPorts = [ cfg.listenPort ];
     })
   ];
diff --git a/nixos/modules/services/misc/taskserver/helper-tool.py b/nixos/modules/services/misc/taskserver/helper-tool.py
index 22a3d8d5311b..fec05728b2b6 100644
--- a/nixos/modules/services/misc/taskserver/helper-tool.py
+++ b/nixos/modules/services/misc/taskserver/helper-tool.py
@@ -90,7 +90,7 @@ def certtool_cmd(*args, **kwargs):
     """
     return subprocess.check_output(
         [CERTTOOL_COMMAND] + list(args),
-        preexec_fn=lambda: os.umask(0077),
+        preexec_fn=lambda: os.umask(0o077),
         stderr=subprocess.STDOUT,
         **kwargs
     )
@@ -164,7 +164,7 @@ def generate_key(org, user):
     pubcert = os.path.join(basedir, "public.cert")
 
     try:
-        os.makedirs(basedir, mode=0700)
+        os.makedirs(basedir, mode=0o700)
 
         certtool_cmd("-p", "--bits", CERT_BITS, "--outfile", privkey)
 
@@ -301,7 +301,7 @@ class Organisation(object):
             return None
         if name not in self.users.keys():
             output = taskd_cmd("add", "user", self.name, name,
-                               capture_stdout=True)
+                               capture_stdout=True, encoding='utf-8')
             key = RE_USERKEY.search(output)
             if key is None:
                 msg = "Unable to find key while creating user {}."
@@ -412,9 +412,9 @@ class Manager(object):
         if org is not None:
             if self.ignore_imperative and is_imperative(name):
                 return
-            for user in org.users.keys():
+            for user in list(org.users.keys()):
                 org.del_user(user)
-            for group in org.groups.keys():
+            for group in list(org.groups.keys()):
                 org.del_group(group)
             taskd_cmd("remove", "org", name)
             del self._lazy_orgs[name]
diff --git a/nixos/tests/taskserver.nix b/nixos/tests/taskserver.nix
index f34782c7059a..b2bd421e231f 100644
--- a/nixos/tests/taskserver.nix
+++ b/nixos/tests/taskserver.nix
@@ -63,6 +63,7 @@ in {
     server = {
       services.taskserver.enable = true;
       services.taskserver.listenHost = "::";
+      services.taskserver.openFirewall = true;
       services.taskserver.fqdn = "server";
       services.taskserver.organisations = {
         testOrganisation.users = [ "alice" "foo" ];