diff --git a/artiq/windows/install.nix b/artiq/windows/install.nix
index cdf3955..22c5ae0 100644
--- a/artiq/windows/install.nix
+++ b/artiq/windows/install.nix
@@ -52,7 +52,7 @@ stdenv.mkDerivation {
     set -e -m
 
     ${qemu.qemu-img} create -f qcow2 c.img ${diskImageSize}
-    ${qemu.runQemu false [
+    ${qemu.runQemu false [] [
       "-boot" "order=d"
       "-drive" "file=c.img,index=0,media=disk,cache=unsafe"
       "-drive" "file=$out/data/windows.iso,index=1,media=cdrom,cache=unsafe"
@@ -65,7 +65,7 @@ stdenv.mkDerivation {
     #!/usr/bin/env bash
     set -e -m
 
-    ${qemu.runQemu false [
+    ${qemu.runQemu false [] [
       "-boot" "order=c"
       "-drive" "file=c.img,index=0,media=disk"
     ]} &
diff --git a/artiq/windows/qemu.nix b/artiq/windows/qemu.nix
index 5601160..0cd52c4 100644
--- a/artiq/windows/qemu.nix
+++ b/artiq/windows/qemu.nix
@@ -9,17 +9,24 @@ with pkgs;
 
 let
   qemu-img = "${qemu_kvm}/bin/qemu-img";
-  runQemu = isolateNetwork: extraArgs:
+  runQemu = isolateNetwork: forwardedPorts: extraArgs:
     let
       restrict =
         if isolateNetwork
         then "on"
         else "off";
+      nc = "${netcat}/bin/nc";
+      # use netcat instead of `tcp:…` to allow multiple connections
+      guestfwds =
+        builtins.concatStringsSep ""
+        (map ({ listenAddr, targetAddr, port }:
+          ",guestfwd=tcp:${listenAddr}:${toString port}-cmd:${nc}\\ ${targetAddr}\\ ${toString port}"
+        ) forwardedPorts);
       args = [
         "-enable-kvm"
         "-m" qemuMem
         "-bios" "${OVMF.fd}/FV/OVMF.fd"
-        "-netdev" "user,id=n1,restrict=${restrict},hostfwd=tcp::2022-:22"
+        "-netdev" "user,id=n1,net=192.168.1.0/24,restrict=${restrict},hostfwd=tcp::2022-:22${guestfwds}"
         "-device" "e1000,netdev=n1"
       ];
       argStr = builtins.concatStringsSep " " (args ++ extraArgs);
diff --git a/artiq/windows/run-test.nix b/artiq/windows/run-test.nix
index 266b5af..3c58f52 100644
--- a/artiq/windows/run-test.nix
+++ b/artiq/windows/run-test.nix
@@ -18,6 +18,13 @@ let
   ssh = cmd: qemu.ssh (escape cmd);
   scp = qemu.scp;
   condaEnv = "artiq-env";
+  tcpPorts = [ 1380 1381 1382 1383 ];
+  forwardedPorts =
+    map (port: {
+      listenAddr = "192.168.1.50";
+      targetAddr = "192.168.1.50";
+      inherit port;
+    }) tcpPorts;
 in
 
 stdenv.mkDerivation {
@@ -31,7 +38,7 @@ stdenv.mkDerivation {
     cat > $out/bin/run.sh << EOF
     # +1 day from last modification of the disk image
     CLOCK=$(date -Is -d @$(expr $(stat -c %Y ${diskImage}) + 86400))
-    ${qemu.runQemu true [
+    ${qemu.runQemu true forwardedPorts [
       "-boot" "order=c"
       "-snapshot"
       "-drive" "file=${diskImage},index=0,media=disk,cache=unsafe"