diff --git a/modules/scripts/onchange.nix b/modules/scripts/onchange.nix
index c18b8b01..78e36bf4 100644
--- a/modules/scripts/onchange.nix
+++ b/modules/scripts/onchange.nix
@@ -1,23 +1,35 @@
+{ withSystem, ... }:
+
+let
+  name = "onchange";
+in
 {
+  perSystem =
+    { pkgs, ... }:
+    with pkgs;
+    {
+      packages.${name} = writeShellApplication {
+        inherit name;
+
+        runtimeInputs = [
+          coreutils
+          entr
+        ];
+
+        text = ''
+          PATTERN="$1"
+          shift 1
+
+          find . -path "$PATTERN" -type f | entr -cs "$@"
+        '';
+      };
+    };
+
   flake.modules.homeManager.base =
     { pkgs, ... }:
     {
       home.packages = [
-        (pkgs.writeShellApplication {
-          name = "onchange";
-
-          runtimeInputs = with pkgs; [
-            coreutils
-            entr
-          ];
-
-          text = ''
-            PATTERN="$1"
-            shift 1
-
-            find . -path "$PATTERN" -type f | entr -cs "$@"
-          '';
-        })
+        (withSystem pkgs.system (psArgs: psArgs.config.packages.${name}))
       ];
     };
 }
diff --git a/modules/scripts/ptest.nix b/modules/scripts/ptest.nix
new file mode 100644
index 00000000..a0cfa6eb
--- /dev/null
+++ b/modules/scripts/ptest.nix
@@ -0,0 +1,42 @@
+{ withSystem, ... }:
+
+let
+  name = "ptest";
+in
+{
+  perSystem =
+    psArgs@{ pkgs, ... }:
+    with pkgs;
+    {
+      packages.${name} = writeShellApplication {
+        inherit name;
+
+        runtimeInputs = [
+          psArgs.config.packages.onchange
+        ];
+
+        text = ''
+          command="phpunit"
+          args=("--colors")
+
+          bin="vendor/bin"
+
+          if [[ -x "$bin/pest" ]]; then
+            command="pest"
+            args=()
+          fi
+
+          onchange "**/*.php" \
+            "$bin/$command ''${args[*]} $*"
+        '';
+      };
+    };
+
+  flake.modules.homeManager.base =
+    { pkgs, ... }:
+    {
+      home.packages = [
+        (withSystem pkgs.system (psArgs: psArgs.config.packages.${name}))
+      ];
+    };
+}