diff --git a/tests/hetzner-backend.nix b/tests/hetzner-backend.nix
index 8d040b1bb..7dc338d15 100644
--- a/tests/hetzner-backend.nix
+++ b/tests/hetzner-backend.nix
@@ -16,6 +16,7 @@ let
         ];
 
         networking.useDHCP = false;
+        networking.firewall.enable = false;
 
         # We don't want to include everything from qemu-vm.nix,
         # so we're going to just pick the options we need (and
@@ -241,9 +242,9 @@ let
     ] ++ (qemuNICFlags 1 1 (builtins.add targetId 1));
   in concatStringsSep " " flags;
 
-in makeTest ({ pkgs, ... }:
-{
+in makeTest {
   nodes.coordinator = {
+    networking.firewall.enable = false;
     environment.systemPackages = let
       testNixops = overrideDerivation nixops (o: {
         postPatch = ''
@@ -261,7 +262,7 @@ in makeTest ({ pkgs, ... }:
           # ... and this is for other requirements for a basic deployment.
           pkgs.stdenv pkgs.busybox pkgs.module_init_tools pkgs.grub2
           pkgs.xfsprogs pkgs.btrfsProgs pkgs.docbook_xsl_ns pkgs.libxslt
-          pkgs.docbook5 pkgs.ntp
+          pkgs.docbook5 pkgs.ntp pkgs.perlPackages.ArchiveCpio
           # Firmware used in <nixpkgs/nixos/modules/installer/scan/not-detected.nix>
           pkgs.firmwareLinuxNonfree
         ];
@@ -367,4 +368,4 @@ in makeTest ({ pkgs, ... }:
       $target2->succeed("mount | grep -F 'on / type btrfs'");
     };
   '';
-})
+}
diff --git a/tests/none-backend.nix b/tests/none-backend.nix
index 5155d2ffa..2de924d89 100644
--- a/tests/none-backend.nix
+++ b/tests/none-backend.nix
@@ -3,10 +3,7 @@
 with import <nixpkgs/nixos/lib/testing.nix> { inherit system; };
 with pkgs.lib;
 
-makeTest ({ pkgs, ... }:
-
 let
-
   # Physical NixOps model.
   physical = pkgs.writeText "physical.nix"
     ''
@@ -38,6 +35,7 @@ let
         target1 =
           { config, pkgs, ... }:
           { services.openssh.enable = true;
+            networking.firewall.enable = false;
             users.extraUsers.root.openssh.authorizedKeys.keyFiles = [ ./id_test.pub ];
             ${optionalString (n == 1) ''
               environment.systemPackages = [ pkgs.vim ];
@@ -63,6 +61,7 @@ let
         target2 =
           { config, pkgs, ... }:
           { services.openssh.enable = true;
+            networking.firewall.enable = false;
             users.extraUsers.root.openssh.authorizedKeys.keyFiles = [ ./id_test.pub ];
             ${optionalString (n == 3) ''
               services.httpd.enable = true;
@@ -76,13 +75,15 @@ let
 
 in
 
-{
+makeTest {
 
   nodes =
     { coordinator =
         { config, pkgs, ... }:
         { environment.systemPackages =
-            [ nixops pkgs.stdenv pkgs.vim pkgs.apacheHttpd pkgs.busybox pkgs.module_init_tools ];
+            [ nixops pkgs.stdenv pkgs.vim pkgs.apacheHttpd pkgs.busybox
+              pkgs.module_init_tools pkgs.perlPackages.ArchiveCpio ];
+          networking.firewall.enable = false;
           virtualisation.writableStore = true;
         };
 
@@ -91,6 +92,7 @@ in
         { services.openssh.enable = true;
           virtualisation.memorySize = 512;
           virtualisation.writableStore = true;
+          networking.firewall.enable = false;
           users.extraUsers.root.openssh.authorizedKeys.keyFiles = [ ./id_test.pub ];
         };
 
@@ -99,6 +101,7 @@ in
         { services.openssh.enable = true;
           virtualisation.memorySize = 512;
           virtualisation.writableStore = true;
+          networking.firewall.enable = false;
           users.extraUsers.root.openssh.authorizedKeys.keyFiles = [ ./id_test.pub ];
         };
     };
@@ -176,4 +179,4 @@ in
 
     '';
 
-})
+}