diff --git a/nixos/doc/manual/development/running-nixos-tests-interactively.xml b/nixos/doc/manual/development/running-nixos-tests-interactively.xml
index 31216874c70..a11a9382764 100644
--- a/nixos/doc/manual/development/running-nixos-tests-interactively.xml
+++ b/nixos/doc/manual/development/running-nixos-tests-interactively.xml
@@ -38,7 +38,12 @@ starting VDE switch for network 1
  </para>
 
  <para>
-  The machine state is kept across VM restarts in
-  <filename>/tmp/vm-state-</filename><varname>machinename</varname>.
+   You can re-use the VM states coming from a previous run
+   by setting the <command>--keep-vm-state</command> flag.
+<screen>
+<prompt>$ </prompt>./result/bin/nixos-run-vms --keep-vm-state
+</screen>
+  The machine state is stored in the
+  <filename>$TMPDIR/vm-state-</filename><varname>machinename</varname> directory.
  </para>
 </section>
diff --git a/nixos/doc/manual/release-notes/rl-2009.xml b/nixos/doc/manual/release-notes/rl-2009.xml
index 4648681597c..c2f26371d66 100644
--- a/nixos/doc/manual/release-notes/rl-2009.xml
+++ b/nixos/doc/manual/release-notes/rl-2009.xml
@@ -675,6 +675,12 @@ systemd.services.nginx.serviceConfig.ReadWritePaths = [ "/var/www" ];
      <package>nextcloud18</package> before upgrading to <package>nextcloud19</package>
      since Nextcloud doesn't support upgrades across multiple major versions.
     </para>
+     <para>
+       The <literal>nixos-run-vms</literal> script now deletes the
+       previous run machines states on test startup. You can use the
+       <literal>--keep-vm-state</literal> flag to match the previous
+       behaviour and keep the same VM state between different test runs.
+     </para>
    </listitem>
   </itemizedlist>
  </section>
diff --git a/nixos/lib/test-driver/test-driver.py b/nixos/lib/test-driver/test-driver.py
index e7b05968b07..f454b052dc3 100644
--- a/nixos/lib/test-driver/test-driver.py
+++ b/nixos/lib/test-driver/test-driver.py
@@ -4,6 +4,7 @@ from queue import Queue, Empty
 from typing import Tuple, Any, Callable, Dict, Iterator, Optional, List
 from xml.sax.saxutils import XMLGenerator
 import _thread
+import argparse
 import atexit
 import base64
 import codecs
@@ -751,6 +752,11 @@ class Machine:
 
         self.log("QEMU running (pid {})".format(self.pid))
 
+    def cleanup_statedir(self) -> None:
+        self.log("delete the VM state directory")
+        if os.path.isfile(self.state_dir):
+            shutil.rmtree(self.state_dir)
+
     def shutdown(self) -> None:
         if not self.booted:
             return
@@ -889,6 +895,15 @@ def subtest(name: str) -> Iterator[None]:
 
 
 if __name__ == "__main__":
+    arg_parser = argparse.ArgumentParser()
+    arg_parser.add_argument(
+        "-K",
+        "--keep-vm-state",
+        help="re-use a VM state coming from a previous run",
+        action="store_true",
+    )
+    (cli_args, vm_scripts) = arg_parser.parse_known_args()
+
     log = Logger()
 
     vlan_nrs = list(dict.fromkeys(os.environ.get("VLANS", "").split()))
@@ -896,8 +911,10 @@ if __name__ == "__main__":
     for nr, vde_socket, _, _ in vde_sockets:
         os.environ["QEMU_VDE_SOCKET_{}".format(nr)] = vde_socket
 
-    vm_scripts = sys.argv[1:]
     machines = [create_machine({"startCommand": s}) for s in vm_scripts]
+    for machine in machines:
+        if not cli_args.keep_vm_state:
+            machine.cleanup_statedir()
     machine_eval = [
         "{0} = machines[{1}]".format(m.name, idx) for idx, m in enumerate(machines)
     ]
@@ -911,7 +928,6 @@ if __name__ == "__main__":
                     continue
                 log.log("killing {} (pid {})".format(machine.name, machine.pid))
                 machine.process.kill()
-
             for _, _, process, _ in vde_sockets:
                 process.terminate()
         log.close()