diff --git a/clients/quadraticserver/dav.nix b/clients/quadraticserver/dav.nix
index 19e97d3..fec4def 100644
--- a/clients/quadraticserver/dav.nix
+++ b/clients/quadraticserver/dav.nix
@@ -1,4 +1,4 @@
-{ config, ... }:
+{ config, pkgs, ... }:
 {
   services =
     let
@@ -10,12 +10,15 @@
         hostname = domain;
         appSecretFile = config.age.secrets."davSecret.age".path;
         adminPasswordFile = config.age.secrets."davPassword.age".path;
+        nginx = null;
+
+        # https://github.com/NixOS/nixpkgs/pull/457476#issuecomment-3678028689
+        package = pkgs.callPackage ../../lib/tempVendoredDavis.nix { };
 
         poolConfig = with config.services.caddy; {
           "listen.owner" = user;
           "listen.group" = group;
         };
-        nginx = null;
       };
 
       caddy.virtualHosts."${domain}".extraConfig = ''
diff --git a/lib/tempVendoredDavis.nix b/lib/tempVendoredDavis.nix
new file mode 100644
index 0000000..423583e
--- /dev/null
+++ b/lib/tempVendoredDavis.nix
@@ -0,0 +1,46 @@
+{
+  lib,
+  fetchFromGitHub,
+  php,
+  nixosTests,
+}:
+
+php.buildComposerProject2 (finalAttrs: {
+  pname = "davis";
+  version = "5.3.0";
+
+  src = fetchFromGitHub {
+    owner = "tchapi";
+    repo = "davis";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-YLVfcoC8cIcCfi7R2zWXNxD4P+KIXOCL+MqFEt2Z7Tc=";
+  };
+
+  vendorHash = "sha256-ub2iv4455AAP9ohN2Zh+8DCbYT1uJOasMeZ/P7tDdw0=";
+
+  composerNoPlugins = false;
+
+  postInstall = ''
+    chmod -R u+w $out/share
+    # Only include the files needed for runtime in the derivation
+    mv $out/share/php/davis/{migrations,public,src,config,bin,templates,tests,translations,vendor,symfony.lock,composer.json,composer.lock} $out
+    # Save the upstream .env file for reference, but rename it so it is not loaded
+    mv $out/share/php/davis/.env $out/env-upstream
+    rm -rf "$out/share"
+  '';
+
+  passthru = {
+    php = php;
+    tests = {
+      inherit (nixosTests) davis;
+    };
+  };
+
+  meta = {
+    changelog = "https://github.com/tchapi/davis/releases/tag/v${finalAttrs.version}";
+    homepage = "https://github.com/tchapi/davis";
+    description = "Simple CardDav and CalDav server inspired by Baïkal";
+    license = lib.licenses.mit;
+    maintainers = with lib.maintainers; [ ramblurr ];
+  };
+})