diff --git a/flake.lock b/flake.lock
index f18d7df0..3b51c7b3 100644
--- a/flake.lock
+++ b/flake.lock
@@ -18,11 +18,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1719468428,
-        "narHash": "sha256-vN5xJAZ4UGREEglh3lfbbkIj+MPEYMuqewMn4atZFaQ=",
+        "lastModified": 1724657323,
+        "narHash": "sha256-LxemfQkxQ74IaXo2BJdFVjGou9/Vvw2Mj0qO3uakwUM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "1e3deb3d8a86a870d925760db1a5adecc64d329d",
+        "rev": "e75de2f317616a27adec8ef2821d93bf3749fcd0",
         "type": "github"
       },
       "original": {
diff --git a/pkgs/libxml2/2.12.nix b/pkgs/libxml2/2.12.nix
new file mode 100644
index 00000000..eed62982
--- /dev/null
+++ b/pkgs/libxml2/2.12.nix
@@ -0,0 +1,71 @@
+{ stdenv
+, lib
+, fetchurl
+, pkg-config
+, autoreconfHook
+, findXMLCatalogs
+, libiconv
+, icuSupport ? false
+, icu
+}:
+
+stdenv.mkDerivation (finalAttrs: {
+  pname = "libxml2";
+  version = "2.12.9";
+
+  outputs = [ "bin" "dev" "out" ];
+  outputMan = "bin";
+
+  src = fetchurl {
+    url = "mirror://gnome/sources/libxml2/${lib.versions.majorMinor finalAttrs.version}/libxml2-${finalAttrs.version}.tar.xz";
+    hash = "sha256-WZEttTarVqOZZInqApl2jHvP/lcWnwI15/liqR9INZA=";
+  };
+
+  strictDeps = true;
+
+  nativeBuildInputs = [
+    pkg-config
+    autoreconfHook
+  ];
+
+  propagatedBuildInputs = [
+    findXMLCatalogs
+  ] ++ lib.optionals stdenv.isDarwin [
+    libiconv
+  ] ++ lib.optionals icuSupport [
+    icu
+  ];
+
+  configureFlags = [
+    "--exec-prefix=${placeholder "dev"}"
+    (lib.withFeature icuSupport "icu")
+    "--without-python"
+  ];
+
+  enableParallelBuilding = true;
+
+  doCheck =
+    (stdenv.hostPlatform == stdenv.buildPlatform) &&
+    stdenv.hostPlatform.libc != "musl";
+  preCheck = lib.optional stdenv.isDarwin ''
+    export DYLD_LIBRARY_PATH="$PWD/.libs:$DYLD_LIBRARY_PATH"
+  '';
+
+  preConfigure = lib.optionalString (lib.versionAtLeast stdenv.hostPlatform.darwinMinVersion "11") ''
+    MACOSX_DEPLOYMENT_TARGET=10.16
+  '';
+
+  postFixup = ''
+    moveToOutput bin/xml2-config "$dev"
+    moveToOutput lib/xml2Conf.sh "$dev"
+  '';
+
+  meta = with lib; {
+    homepage = "https://gitlab.gnome.org/GNOME/libxml2";
+    description = "XML parsing library for C";
+    license = licenses.mit;
+    platforms = platforms.all;
+    maintainers = with maintainers; [ eelco jtojnar ];
+    pkgConfigModules = [ "libxml-2.0" ];
+  };
+})
diff --git a/pkgs/phps.nix b/pkgs/phps.nix
index 36739d53..49f6c27d 100644
--- a/pkgs/phps.nix
+++ b/pkgs/phps.nix
@@ -8,17 +8,27 @@ prev:
 let
   packageOverrides = import ./package-overrides.nix prev;
 
+  libxml2_12 = prev.callPackage ./libxml2/2.12.nix { };
+
   _mkArgs =
     args:
 
     let
+      libxml2 =
+        if prev.lib.versionAtLeast args.version "8.1"
+        then prev.libxml2
+        else libxml2_12;
+
+      # Use a consistent libxml2 version.
+      libxslt = prev.libxslt.override { inherit libxml2; };
+
       pcre2 =
         if prev.lib.versionAtLeast args.version "7.3"
         then prev.pcre2
         else prev.pcre;
     in
     {
-      inherit packageOverrides pcre2;
+      inherit packageOverrides libxml2 pcre2;
 
       phpAttrsOverrides =
         attrs:
@@ -58,7 +68,7 @@ let
               "--enable-hash"
 
               "--enable-libxml"
-              "--with-libxml-dir=${prev.libxml2.dev}"
+              "--with-libxml-dir=${libxml2.dev}"
             ]
             ++ prev.lib.optionals (prev.lib.versions.majorMinor args.version == "7.3") [
               # Force use of pkg-config.
@@ -98,7 +108,7 @@ let
             + prev.lib.optionalString (prev.lib.versionAtLeast args.version "7.3" && prev.lib.versionOlder args.version "7.4") " -Wno-int-conversion";
         };
 
-      # For passing pcre2 to php-packages.nix.
+      # For passing libxml2 and pcre2 to php-packages.nix.
       callPackage =
         cpFn:
         cpArgs:
@@ -108,7 +118,7 @@ let
 
           # Only pass these attributes if the package function actually expects them.
           prev.lib.filterAttrs (key: _v: builtins.hasAttr key prevArgs) {
-            inherit pcre2;
+            inherit libxml2 libxslt pcre2;
 
             # For passing pcre2 to stuff called with callPackage in php-packages.nix.
             pkgs =
@@ -117,7 +127,7 @@ let
                 prev.lib.makeScope
                   prev.newScope
                   (self: {
-                    inherit pcre2;
+                    inherit libxml2 libxslt pcre2;
                   })
               );
           }