diff --git a/tests/default.nix b/tests/default.nix
index e8c48d6..8961842 100644
--- a/tests/default.nix
+++ b/tests/default.nix
@@ -12,6 +12,7 @@ let
     ./hello.nix
     ./log.nix
     ./networking.nix
+    ./posix.nix
     ./solo5/multi.nix
     ./vmm_x86.nix
     ./x86.nix
diff --git a/tests/posix.dhall b/tests/posix.dhall
index 0b6a6dd..824b3d4 100644
--- a/tests/posix.dhall
+++ b/tests/posix.dhall
@@ -1,6 +1,4 @@
-let Test = ./test.dhall ? env:DHALL_GENODE_TEST
-
-let Genode = Test.Genode
+let Genode = env:DHALL_GENODE
 
 let Prelude = Genode.Prelude
 
@@ -31,19 +29,22 @@ in  λ(params : { bash : Text, coreutils : Text, script : Text }) →
                               <dir name="dev"> <log name="stdout" label="stdout"/> <log name="stderr" label="stderr"/> <null/> <pipe/> <rtc/> <zero/> </dir>
                               <dir name="usr"><dir name="bin"><symlink name="env" target="${params.coreutils}/bin/env"/></dir></dir>
                               <dir name="tmp"><ram/></dir>
-                              <dir name="nix"><fs label="nix" root="nix"/></dir>
+                              <dir name="nix"><dir name="store"><fs label="nix-store"/></dir></dir>
                               </vfs>
                               ''
                           ]
                         , policies =
                           [ Init.Config.Policy::{
                             , service = "File_system"
-                            , label =
-                                Init.LabelSelector.Type.Partial
-                                  { prefix = Some "shell", suffix = None Text }
+                            , label = Init.LabelSelector.prefix "shell"
                             , attributes = toMap
                                 { root = "/", writeable = "yes" }
                             }
+                          , Init.Config.Policy::{
+                            , service = "File_system"
+                            , label = Init.LabelSelector.prefix "vfs_rom"
+                            , attributes = toMap { root = "/" }
+                            }
                           ]
                         }
                       , provides = [ "File_system" ]
@@ -58,7 +59,7 @@ in  λ(params : { bash : Text, coreutils : Text, script : Text }) →
                             Init.ServiceRoute.parent
                             [ "File_system", "Rtc" ]
                       }
-                , store_rom =
+                , vfs_rom =
                     Child.flat
                       Child.Attributes::{
                       , binary = "cached_fs_rom"
@@ -67,12 +68,6 @@ in  λ(params : { bash : Text, coreutils : Text, script : Text }) →
                         , caps = 256
                         , ram = Genode.units.MiB 4
                         }
-                      , routes =
-                        [ Init.ServiceRoute.parentLabel
-                            "File_system"
-                            (None Text)
-                            (Some "nix")
-                        ]
                       }
                 , shell =
                     Child.flat
@@ -113,7 +108,7 @@ in  λ(params : { bash : Text, coreutils : Text, script : Text }) →
                             }
                           , route =
                               Init.Route.Type.Child
-                                { name = "store_rom"
+                                { name = "vfs_rom"
                                 , label = None Text
                                 , diag = None Bool
                                 }
@@ -123,4 +118,4 @@ in  λ(params : { bash : Text, coreutils : Text, script : Text }) →
                 }
             }
 
-      in  Test::{ children = Test.initToChildren init }
+      in  Init.toChild init Init.Attributes::{=}
diff --git a/tests/posix.nix b/tests/posix.nix
index 5bc991e..f5b43a7 100644
--- a/tests/posix.nix
+++ b/tests/posix.nix
@@ -1,33 +1,30 @@
-{ pkgs, legacyPackages, ... }:
-with pkgs;
-
-let
-  inherit (legacyPackages) bash coreutils;
-  script = with legacyPackages;
-    writeTextFile {
-      name = "posix.sh";
-      text = ''
-        export PATH=${
-          lib.makeSearchPathOutput "bin" "bin"
-          (with legacyPackages; [ bash hello coreutils ])
-        }
-        set -v
-        time ls -lR /nix
-        sleep 1
-        hello -v
-        sleep 1
-        uname -a
-      '';
-    };
-in rec {
+{
   name = "posix";
-  machine = {
-    config = ''
-      ${
-        ./posix.dhall
-      } { bash = \"${bash}\", coreutils = \"${coreutils}\", script = \"${script}\" }'';
-    inputs = map pkgs.genodeSources.depot [ "libc" "posix" "vfs_pipe" "vfs" ]
-      ++ [ bash ];
-    extraPaths = [ script ] ++ (with legacyPackages; [ coreutils hello ]);
+  machine = { pkgs, ... }: {
+    genode.init.children.posix = with pkgs;
+      let
+        script = writeTextFile {
+          name = "posix.sh";
+          text = ''
+            export PATH=${
+              lib.makeSearchPathOutput "bin" "bin" [ bash hello coreutils ]
+            }
+            set -v
+            time ls -lR /nix
+            sleep 1
+            hello -v
+            sleep 1
+            uname -a
+          '';
+        };
+      in {
+        configFile = writeText "posix.child.dhall" ''
+          ${
+            ./posix.dhall
+          } { bash = "${bash}", coreutils = "${coreutils}", script = "${script}" }
+        '';
+        inputs = [ bash hello coreutils ]
+          ++ (with genodePackages; [ cached_fs_rom libc posix vfs vfs_pipe ]);
+      };
   };
 }