diff --git a/flake.nix b/flake.nix
index e20abc5..b407763 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,6 +2,7 @@
   description = "raspberry-pi nixos configuration";
 
   inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/9a9960b98418f8c385f52de3b09a63f9c561427a";
     u-boot-src = {
       flake = false;
       url = "https://ftp.denx.de/pub/u-boot/u-boot-2024.01.tar.bz2";
@@ -36,14 +37,25 @@
     };
   };
 
-  outputs = srcs@{ self, ... }: {
-    overlays = {
-      core = import ./overlays (builtins.removeAttrs srcs [ "self" ]);
-      libcamera = import ./overlays/libcamera.nix (builtins.removeAttrs srcs [ "self" ]);
+  outputs = srcs@{ self, ... }:
+    let
+      pinned = import nixpkgs {
+        system = "aarch64-linux";
+        overlays = with self.overlays; [ core libcamera ];
+      };
+    in
+    {
+      overlays = {
+        core = import ./overlays (builtins.removeAttrs srcs [ "self" ]);
+        libcamera = import ./overlays/libcamera.nix (builtins.removeAttrs srcs [ "self" ]);
+      };
+      nixosModules.raspberry-pi = import ./rpi {
+        inherit pinned;
+        core-overlay = self.overlays.core;
+        libcamera-overlay = self.overlays.libcamera;
+      };
+      packages.aarch64-linux = {
+        linux = pinned.rpi-kernels.latest.kernel;
+      };
     };
-    nixosModules.raspberry-pi = import ./rpi {
-      core-overlay = self.overlays.core;
-      libcamera-overlay = self.overlays.libcamera;
-    };
-  };
 }
diff --git a/rpi/default.nix b/rpi/default.nix
index 1652799..0ac3b8a 100644
--- a/rpi/default.nix
+++ b/rpi/default.nix
@@ -1,4 +1,4 @@
-{ core-overlay, libcamera-overlay }:
+{ pinned, core-overlay, libcamera-overlay }:
 { lib, pkgs, config, ... }:
 
 let cfg = config.raspberry-pi-nix;
@@ -272,7 +272,10 @@ in
         "pcie_brcmstb" # required for the pcie bus to work
         "reset-raspberrypi" # required for vl805 firmware to load
       ];
-      kernelPackages = pkgs.linuxPackagesFor (pkgs.rpi-kernels.latest.kernel);
+      # This pin is not necessary, it would be fine to replace it with
+      # `pkgs.rpi-kernels.latest.kernel`. It is helpful to ensure
+      # cache hits for kernel builds though.
+      kernelPackages = pinned.linuxPackagesFor (pinned.rpi-kernels.latest.kernel);
 
       loader = {
         grub.enable = lib.mkDefault false;