diff --git a/nixos/lib/testing-python.nix b/nixos/lib/testing-python.nix
index 6497b897eafd3a..679c31f3e35461 100644
--- a/nixos/lib/testing-python.nix
+++ b/nixos/lib/testing-python.nix
@@ -32,6 +32,14 @@ rec {
 
       preferLocalBuild = true;
 
+      buildPhase = ''
+        python <<EOF
+        from pydoc import importfile
+        with open('driver-exports', 'w') as fp:
+          fp.write(','.join(dir(importfile('${testDriverScript}'))))
+        EOF
+      '';
+
       doCheck = true;
       checkPhase = ''
         mypy --disallow-untyped-defs \
@@ -50,6 +58,8 @@ rec {
 
           wrapProgram $out/bin/nixos-test-driver \
             --prefix PATH : "${lib.makeBinPath [ qemu_pkg vde2 netpbm coreutils ]}" \
+
+          install -m 0644 -vD driver-exports $out/nix-support/driver-exports
         '';
     };
 
@@ -73,7 +83,9 @@ rec {
           LOGFILE=/dev/null tests='exec(os.environ["testScript"])' ${driver}/bin/nixos-test-driver
         '';
 
-      passthru = driver.passthru;
+      passthru = driver.passthru // {
+        inherit driver;
+      };
 
       inherit pos;
     };
@@ -159,7 +171,10 @@ rec {
 
             echo -n "$testScript" > $out/test-script
             ${lib.optionalString (!skipLint) ''
-              ${python3Packages.black}/bin/black --check --diff $out/test-script
+              PYFLAKES_BUILTINS="$(
+                echo -n ${lib.escapeShellArg (lib.concatStringsSep "," nodeHostNames)},
+                < ${lib.escapeShellArg "${testDriver}/nix-support/driver-exports"}
+              )" ${python3Packages.pyflakes}/bin/pyflakes $out/test-script
             ''}
 
             ln -s ${testDriver}/bin/nixos-test-driver $out/bin/
@@ -193,6 +208,8 @@ rec {
         (node: builtins.match "^[A-z_]([A-z0-9_]+)?$" node == null)
         nodeNames;
 
+      nodeHostNames = map (c: c.config.system.name) (lib.attrValues driver.nodes);
+
     in
     if lib.length invalidNodeNames > 0 then
       throw ''
diff --git a/nixos/tests/acme.nix b/nixos/tests/acme.nix
index 99dd8ec6fd3c1c..6f98b0da37805d 100644
--- a/nixos/tests/acme.nix
+++ b/nixos/tests/acme.nix
@@ -245,7 +245,7 @@ in import ./make-test-python.nix ({ lib, ... }: {
           )
           for line in subject_data.lower().split("\n"):
               if "subject" in line:
-                  print(f"First subject in fullchain.pem: ", line)
+                  print(f"First subject in fullchain.pem: {line}")
                   assert cert_name.lower() in line
                   return
 
diff --git a/nixos/tests/chromium.nix b/nixos/tests/chromium.nix
index 8429d932ae694c..60ecf986d6eed4 100644
--- a/nixos/tests/chromium.nix
+++ b/nixos/tests/chromium.nix
@@ -54,7 +54,8 @@ mapAttrs (channel: chromiumPkg: makeTest rec {
     in "${pkgs.xdotool}/bin/xdotool ${xdoScript}";
   in ''
     import shlex
-    from contextlib import contextmanager, _GeneratorContextManager
+    import re
+    from contextlib import contextmanager
 
 
     # Run as user alice
diff --git a/nixos/tests/containers-custom-pkgs.nix b/nixos/tests/containers-custom-pkgs.nix
index c050e49bc29d2d..1627a2c70c3ca9 100644
--- a/nixos/tests/containers-custom-pkgs.nix
+++ b/nixos/tests/containers-custom-pkgs.nix
@@ -30,5 +30,5 @@ in {
   };
 
   # This test only consists of evaluating the test machine
-  testScript = "";
+  testScript = "pass";
 })
diff --git a/nixos/tests/containers-imperative.nix b/nixos/tests/containers-imperative.nix
index bb207165a02afc..1dcccfc306a353 100644
--- a/nixos/tests/containers-imperative.nix
+++ b/nixos/tests/containers-imperative.nix
@@ -162,6 +162,6 @@ import ./make-test-python.nix ({ pkgs, lib, ... }: {
           machine.fail(
               "nixos-container create b0rk --config-file ${brokenCfg}"
           )
-          machine.succeed(f"test ! -e /var/lib/containers/b0rk")
+          machine.succeed("test ! -e /var/lib/containers/b0rk")
     '';
 })
diff --git a/nixos/tests/custom-ca.nix b/nixos/tests/custom-ca.nix
index 31909188d3a789..7ce1101911db0b 100644
--- a/nixos/tests/custom-ca.nix
+++ b/nixos/tests/custom-ca.nix
@@ -112,6 +112,7 @@ in
     };
 
   testScript = ''
+    from typing import Tuple
     def execute_as(user: str, cmd: str) -> Tuple[int, str]:
         """
         Run a shell command as a specific user.
diff --git a/nixos/tests/jellyfin.nix b/nixos/tests/jellyfin.nix
index f8c2429a7b8d80..cae31a7192582d 100644
--- a/nixos/tests/jellyfin.nix
+++ b/nixos/tests/jellyfin.nix
@@ -24,7 +24,6 @@ import ./make-test-python.nix ({ lib, pkgs, ... }:
       in
       ''
         import json
-        import time
         from urllib.parse import urlencode
 
         machine.wait_for_unit("jellyfin.service")
@@ -101,7 +100,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }:
 
 
         def is_refreshed(_):
-            folders = machine.succeed(api_get(f"/Library/VirtualFolders"))
+            folders = machine.succeed(api_get("/Library/VirtualFolders"))
             folders = json.loads(folders)
             print(folders)
             return all(folder["RefreshStatus"] == "Idle" for folder in folders)
@@ -141,7 +140,7 @@ import ./make-test-python.nix ({ lib, pkgs, ... }:
                 "ffmpeg"
                 + f" -headers 'X-Emby-Authorization:{auth_header}'"
                 + f" -i http://localhost:8096/Videos/{video}/master.m3u8?mediaSourceId={media_source_id}"
-                + f" /tmp/test.mkv"
+                + " /tmp/test.mkv"
             )
 
             duration = machine.succeed(
diff --git a/nixos/tests/networking.nix b/nixos/tests/networking.nix
index 1ea61f99a95139..c8756207f27b6f 100644
--- a/nixos/tests/networking.nix
+++ b/nixos/tests/networking.nix
@@ -511,7 +511,7 @@ let
             machine.sleep(10)
             residue = machine.succeed("ip tuntap list")
             assert (
-                residue is ""
+                residue == ""
             ), "Some virtual interface has not been properly cleaned:\n{}".format(residue)
       '';
     };
@@ -665,10 +665,10 @@ let
             ipv4Residue = machine.succeed("ip -4 route list dev eth0 | head -n-3").strip()
             ipv6Residue = machine.succeed("ip -6 route list dev eth0 | head -n-3").strip()
             assert (
-                ipv4Residue is ""
+                ipv4Residue == ""
             ), "The IPv4 routing table has not been properly cleaned:\n{}".format(ipv4Residue)
             assert (
-                ipv6Residue is ""
+                ipv6Residue == ""
             ), "The IPv6 routing table has not been properly cleaned:\n{}".format(ipv6Residue)
       '';
     };
diff --git a/nixos/tests/nfs/kerberos.nix b/nixos/tests/nfs/kerberos.nix
index 75d1210496b003..5684131f671b13 100644
--- a/nixos/tests/nfs/kerberos.nix
+++ b/nixos/tests/nfs/kerberos.nix
@@ -88,8 +88,8 @@ in
           "kdb5_util create -s -r NFS.TEST -P master_key",
           "systemctl restart kadmind.service kdc.service",
       )
-      server.wait_for_unit(f"kadmind.service")
-      server.wait_for_unit(f"kdc.service")
+      server.wait_for_unit("kadmind.service")
+      server.wait_for_unit("kdc.service")
 
       # create principals
       server.succeed(
@@ -102,8 +102,8 @@ in
       # add principals to server keytab
       server.succeed("kadmin.local ktadd nfs/server.nfs.test")
       server.succeed("systemctl start rpc-gssd.service rpc-svcgssd.service")
-      server.wait_for_unit(f"rpc-gssd.service")
-      server.wait_for_unit(f"rpc-svcgssd.service")
+      server.wait_for_unit("rpc-gssd.service")
+      server.wait_for_unit("rpc-svcgssd.service")
 
       client.wait_for_unit("network-online.target")
 
diff --git a/nixos/tests/printing.nix b/nixos/tests/printing.nix
index 6a1801fb288408..b2f2540fb7a138 100644
--- a/nixos/tests/printing.nix
+++ b/nixos/tests/printing.nix
@@ -50,7 +50,6 @@ in {
   testScript = ''
     import os
     import re
-    import sys
 
     start_all()
 
diff --git a/nixos/tests/shadow.nix b/nixos/tests/shadow.nix
index c51961e1fc68b4..dd2a575b1935a8 100644
--- a/nixos/tests/shadow.nix
+++ b/nixos/tests/shadow.nix
@@ -36,9 +36,9 @@ in import ./make-test-python.nix ({ pkgs, ... }: {
 
     with subtest("Normal login"):
         shadow.send_key("alt-f2")
-        shadow.wait_until_succeeds(f"[ $(fgconsole) = 2 ]")
-        shadow.wait_for_unit(f"getty@tty2.service")
-        shadow.wait_until_succeeds(f"pgrep -f 'agetty.*tty2'")
+        shadow.wait_until_succeeds("[ $(fgconsole) = 2 ]")
+        shadow.wait_for_unit("getty@tty2.service")
+        shadow.wait_until_succeeds("pgrep -f 'agetty.*tty2'")
         shadow.wait_until_tty_matches(2, "login: ")
         shadow.send_chars("emma\n")
         shadow.wait_until_tty_matches(2, "login: emma")
@@ -60,9 +60,9 @@ in import ./make-test-python.nix ({ pkgs, ... }: {
 
     with subtest("Change password"):
         shadow.send_key("alt-f3")
-        shadow.wait_until_succeeds(f"[ $(fgconsole) = 3 ]")
-        shadow.wait_for_unit(f"getty@tty3.service")
-        shadow.wait_until_succeeds(f"pgrep -f 'agetty.*tty3'")
+        shadow.wait_until_succeeds("[ $(fgconsole) = 3 ]")
+        shadow.wait_for_unit("getty@tty3.service")
+        shadow.wait_until_succeeds("pgrep -f 'agetty.*tty3'")
         shadow.wait_until_tty_matches(3, "login: ")
         shadow.send_chars("emma\n")
         shadow.wait_until_tty_matches(3, "login: emma")
@@ -78,9 +78,9 @@ in import ./make-test-python.nix ({ pkgs, ... }: {
         shadow.send_chars("${password3}\n")
         shadow.sleep(2)
         shadow.send_key("alt-f4")
-        shadow.wait_until_succeeds(f"[ $(fgconsole) = 4 ]")
-        shadow.wait_for_unit(f"getty@tty4.service")
-        shadow.wait_until_succeeds(f"pgrep -f 'agetty.*tty4'")
+        shadow.wait_until_succeeds("[ $(fgconsole) = 4 ]")
+        shadow.wait_for_unit("getty@tty4.service")
+        shadow.wait_until_succeeds("pgrep -f 'agetty.*tty4'")
         shadow.wait_until_tty_matches(4, "login: ")
         shadow.send_chars("emma\n")
         shadow.wait_until_tty_matches(4, "login: emma")
@@ -106,9 +106,9 @@ in import ./make-test-python.nix ({ pkgs, ... }: {
 
     with subtest("nologin shell"):
         shadow.send_key("alt-f5")
-        shadow.wait_until_succeeds(f"[ $(fgconsole) = 5 ]")
-        shadow.wait_for_unit(f"getty@tty5.service")
-        shadow.wait_until_succeeds(f"pgrep -f 'agetty.*tty5'")
+        shadow.wait_until_succeeds("[ $(fgconsole) = 5 ]")
+        shadow.wait_for_unit("getty@tty5.service")
+        shadow.wait_until_succeeds("pgrep -f 'agetty.*tty5'")
         shadow.wait_until_tty_matches(5, "login: ")
         shadow.send_chars("layla\n")
         shadow.wait_until_tty_matches(5, "login: layla")
diff --git a/nixos/tests/unbound.nix b/nixos/tests/unbound.nix
index e24c3ef6c99d28..fcfa222299c886 100644
--- a/nixos/tests/unbound.nix
+++ b/nixos/tests/unbound.nix
@@ -192,7 +192,6 @@ import ./make-test-python.nix ({ pkgs, lib, ... }:
 
     testScript = { nodes, ... }: ''
       import typing
-      import json
 
       zone = "example.local."
       records = [("AAAA", "abcd::eeff"), ("A", "1.2.3.4")]
diff --git a/nixos/tests/virtualbox.nix b/nixos/tests/virtualbox.nix
index 0a7369b0fa2aae..09314d93b7d04e 100644
--- a/nixos/tests/virtualbox.nix
+++ b/nixos/tests/virtualbox.nix
@@ -226,18 +226,16 @@ let
 
 
       def create_vm_${name}():
-          # fmt: off
-          vbm(f"createvm --name ${name} ${createFlags}")
-          vbm(f"modifyvm ${name} ${vmFlags}")
-          vbm(f"setextradata ${name} VBoxInternal/PDM/HaltOnReset 1")
-          vbm(f"storagectl ${name} ${controllerFlags}")
-          vbm(f"storageattach ${name} ${diskFlags}")
-          vbm(f"sharedfolder add ${name} ${sharedFlags}")
-          vbm(f"sharedfolder add ${name} ${nixstoreFlags}")
+          vbm("createvm --name ${name} ${createFlags}")
+          vbm("modifyvm ${name} ${vmFlags}")
+          vbm("setextradata ${name} VBoxInternal/PDM/HaltOnReset 1")
+          vbm("storagectl ${name} ${controllerFlags}")
+          vbm("storageattach ${name} ${diskFlags}")
+          vbm("sharedfolder add ${name} ${sharedFlags}")
+          vbm("sharedfolder add ${name} ${nixstoreFlags}")
           cleanup_${name}()
 
           ${mkLog "$HOME/VirtualBox VMs/${name}/Logs/VBox.log" "HOST-${name}"}
-          # fmt: on
 
 
       def destroy_vm_${name}():
@@ -259,9 +257,7 @@ let
 
       def wait_for_ip_${name}(interface):
           property = f"/VirtualBox/GuestInfo/Net/{interface}/V4/IP"
-          # fmt: off
           getip = f"VBoxManage guestproperty get ${name} {property} | sed -n -e 's/^Value: //p'"
-          # fmt: on
 
           ip = machine.succeed(
               ru(
@@ -394,9 +390,7 @@ let
 
       machine.wait_for_x()
 
-      # fmt: off
       ${mkLog "$HOME/.config/VirtualBox/VBoxSVC.log" "HOST-SVC"}
-      # fmt: on
 
       ${testScript}
       # (keep black happy)
diff --git a/nixos/tests/yggdrasil.nix b/nixos/tests/yggdrasil.nix
index 0b58ad29aa2b12..0e75ed54db2812 100644
--- a/nixos/tests/yggdrasil.nix
+++ b/nixos/tests/yggdrasil.nix
@@ -147,7 +147,7 @@ in import ./make-test-python.nix ({ pkgs, ...} : {
       # If Alice can talk to Carol, then Bob's outbound peering and Carol's
       # local peering have succeeded and everybody is connected.
       alice.wait_until_succeeds(f"ping -c 1 {carol_ip6}")
-      alice.succeed(f"ping -c 1 ${bobIp6}")
+      alice.succeed("ping -c 1 ${bobIp6}")
 
       bob.succeed("ping -c 1 ${aliceIp6}")
       bob.succeed(f"ping -c 1 {carol_ip6}")