diff --git a/pkgs/darwin-installer/configuration.nix b/pkgs/darwin-installer/configuration.nix
index e224285d..7aafbfd4 100644
--- a/pkgs/darwin-installer/configuration.nix
+++ b/pkgs/darwin-installer/configuration.nix
@@ -3,63 +3,8 @@
 with lib;
 
 {
-  imports = [ <user-darwin-config> ];
+  imports = [ <user-darwin-config> ./installer.nix ];
 
   users.nix.configureBuildUsers = true;
   users.knownGroups = [ "nixbld" ];
-
-  system.activationScripts.preUserActivation.text = mkBefore ''
-    PATH=/nix/var/nix/profiles/default/bin:$PATH
-
-    i=y
-    if ! test -L /etc/bashrc && ! tail -n1 /etc/bashrc | grep -q /etc/static/bashrc; then
-        if test -t 1; then
-            read -p "Would you like to load darwin configuration in /etc/bashrc? [y/n] " i
-        fi
-        case "$i" in
-            y|Y)
-                sudo ${pkgs.gnused}/bin/sed -i '\,/etc/static/bashrc,d' /etc/bashrc
-                echo 'if test -e /etc/static/bashrc; then . /etc/static/bashrc; fi' | sudo tee -a /etc/bashrc
-                ;;
-        esac
-    fi
-
-    if ! test -L /etc/zshrc && ! tail -n1 /etc/zshrc | grep -q /etc/static/zshrc; then
-        if test -t 1; then
-            read -p "Would you like to load darwin configuration in /etc/zshrc? [y/n] " i
-        fi
-        case "$i" in
-            y|Y)
-                sudo ${pkgs.gnused}/bin/sed -i '\,/etc/static/zshrc,d' /etc/zshrc
-                echo 'if test -e /etc/static/zshrc; then . /etc/static/zshrc; fi' | sudo tee -a /etc/zshrc
-                ;;
-        esac
-    fi
-
-    if ! test -L /run; then
-      if test -t 1; then
-          read -p "Would you like to create /run? [y/n] " i
-      fi
-      case "$i" in
-          y|Y)
-              if ! grep -q '^run\b' /etc/synthetic.conf 2>/dev/null; then
-                  echo "setting up /run via /etc/synthetic.conf..."
-                  echo -e "run\tprivate/var/run" | sudo tee -a /etc/synthetic.conf >/dev/null
-                  /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B &>/dev/null || true
-                  /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t &>/dev/null || true
-                  if ! test -L /run; then
-                    echo "warning: apfs.util failed to symlink /run"
-                  fi
-              fi
-              if ! test -L /run; then
-                  echo "setting up /run..."
-                  sudo ln -sfn private/var/run /run
-              fi
-              if ! test -L /run; then
-                echo "warning: failed to symlink /run"
-              fi
-              ;;
-      esac
-    fi
-  '';
 }
diff --git a/pkgs/darwin-installer/installer.nix b/pkgs/darwin-installer/installer.nix
new file mode 100644
index 00000000..1c58976d
--- /dev/null
+++ b/pkgs/darwin-installer/installer.nix
@@ -0,0 +1,60 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+{
+  system.activationScripts.preUserActivation.text = mkBefore ''
+    PATH=/nix/var/nix/profiles/default/bin:$PATH
+
+    i=y
+    if ! test -L /etc/bashrc && ! tail -n1 /etc/bashrc | grep -q /etc/static/bashrc; then
+        if test -t 1; then
+            read -p "Would you like to load darwin configuration in /etc/bashrc? [y/n] " i
+        fi
+        case "$i" in
+            y|Y)
+                sudo ${pkgs.gnused}/bin/sed -i '\,/etc/static/bashrc,d' /etc/bashrc
+                echo 'if test -e /etc/static/bashrc; then . /etc/static/bashrc; fi' | sudo tee -a /etc/bashrc
+                ;;
+        esac
+    fi
+
+    if ! test -L /etc/zshrc && ! tail -n1 /etc/zshrc | grep -q /etc/static/zshrc; then
+        if test -t 1; then
+            read -p "Would you like to load darwin configuration in /etc/zshrc? [y/n] " i
+        fi
+        case "$i" in
+            y|Y)
+                sudo ${pkgs.gnused}/bin/sed -i '\,/etc/static/zshrc,d' /etc/zshrc
+                echo 'if test -e /etc/static/zshrc; then . /etc/static/zshrc; fi' | sudo tee -a /etc/zshrc
+                ;;
+        esac
+    fi
+
+    if ! test -L /run; then
+      if test -t 1; then
+          read -p "Would you like to create /run? [y/n] " i
+      fi
+      case "$i" in
+          y|Y)
+              if ! grep -q '^run\b' /etc/synthetic.conf 2>/dev/null; then
+                  echo "setting up /run via /etc/synthetic.conf..."
+                  echo -e "run\tprivate/var/run" | sudo tee -a /etc/synthetic.conf >/dev/null
+                  /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -B &>/dev/null || true
+                  /System/Library/Filesystems/apfs.fs/Contents/Resources/apfs.util -t &>/dev/null || true
+                  if ! test -L /run; then
+                    echo "warning: apfs.util failed to symlink /run"
+                  fi
+              fi
+              if ! test -L /run; then
+                  echo "setting up /run..."
+                  sudo ln -sfn private/var/run /run
+              fi
+              if ! test -L /run; then
+                echo "warning: failed to symlink /run"
+              fi
+              ;;
+      esac
+    fi
+  '';
+}