diff --git a/nix/ext/pg_net.nix b/nix/ext/pg_net.nix
index f769bad314..d004b9e491 100644
--- a/nix/ext/pg_net.nix
+++ b/nix/ext/pg_net.nix
@@ -7,14 +7,31 @@
   libuv,
   makeWrapper,
   switch-ext-version,
-  curl_8_6,
+  curl,
+  libidn2,
+  libpsl,
+  libunistring,
+  libiconv,
   latestOnly ? false,
 }:
 
 let
-  curl = curl_8_6;
-in
-let
+  # nixpkgs builds libunistring against gnu libiconv on darwin, which collides with apple's in the cli bundle
+  curlAppleIconv =
+    let
+      libunistringApple = libunistring.override { libiconvReal = libiconv; };
+      libidn2Apple = libidn2.override { libunistring = libunistringApple; };
+      libpslApple =
+        (libpsl.override {
+          libidn2 = libidn2Apple;
+          libunistring = libunistringApple;
+        }).overrideAttrs
+          { env.NIX_LDFLAGS = "-liconv"; };
+    in
+    curl.override {
+      libidn2 = libidn2Apple;
+      libpsl = libpslApple;
+    };
   pname = "pg_net";
   build =
     version: hash:
@@ -22,7 +39,7 @@ let
       inherit pname version;
 
       buildInputs = [
-        curl
+        (if stdenv.isDarwin then curlAppleIconv else curl)
         postgresql
       ]
       ++ lib.optional (version == "0.6") libuv;
@@ -35,6 +52,9 @@ let
       };
 
       buildPhase = ''
+        ${lib.optionalString (lib.versionOlder version "0.20.4") ''
+          export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -DCURL_DISABLE_TYPECHECK"
+        ''}
         make PG_CONFIG=${postgresql}/bin/pg_config
       '';
 
diff --git a/nix/ext/postgis.nix b/nix/ext/postgis.nix
index 699479b655..b388153d17 100644
--- a/nix/ext/postgis.nix
+++ b/nix/ext/postgis.nix
@@ -22,16 +22,20 @@
   coreutils,
   cgal,
   sfcgal,
+  boost,
+  icu75,
   latestOnly ? false,
 }:
 
 let
+  boostIcu75 = boost.override { icu = icu75; };
   # Hold cgal back to 6.0.2 until nixpkgs bumps sfcgal past 2.2.0 (incompatible with CGAL 6.1+).
   sfcgal' =
     assert lib.assertMsg (lib.versionAtLeast "2.2.0" sfcgal.version)
       "sfcgal ${sfcgal.version} is newer than 2.2.0, drop the cgal 6.0.2 pin";
     sfcgal.override {
-      cgal = cgal.overrideAttrs (_: {
+      boost = boostIcu75;
+      cgal = (cgal.override { boost = boostIcu75; }).overrideAttrs (_: {
         version = "6.0.2";
         src = fetchurl {
           url = "https://github.com/CGAL/cgal/releases/download/v6.0.2/CGAL-6.0.2.tar.xz";
diff --git a/nix/nixpkgs.nix b/nix/nixpkgs.nix
index 70c259af3c..6dbf7dccd4 100644
--- a/nix/nixpkgs.nix
+++ b/nix/nixpkgs.nix
@@ -17,7 +17,6 @@
               };
             in
             _final: _prev: {
-              curl_8_6 = oldstable.curl;
               v8_oldstable = oldstable.v8;
             }
           )
diff --git a/nix/pgbouncer.nix b/nix/pgbouncer.nix
index 91e42c230d..3123f4e26e 100644
--- a/nix/pgbouncer.nix
+++ b/nix/pgbouncer.nix
@@ -6,7 +6,7 @@
   libevent,
   c-ares,
   pkg-config,
-  systemd,
+  systemdLibs,
   nixosTests,
   pandoc,
   python3,
@@ -31,7 +31,7 @@ stdenv.mkDerivation rec {
     openssl
     c-ares
   ]
-  ++ lib.optional stdenv.hostPlatform.isLinux systemd;
+  ++ lib.optional stdenv.hostPlatform.isLinux systemdLibs;
   enableParallelBuilding = true;
   configureFlags = lib.optional stdenv.hostPlatform.isLinux "--with-systemd";
 
diff --git a/nix/postgresql/generic.nix b/nix/postgresql/generic.nix
index 0c5cb589a0..f07dd75690 100644
--- a/nix/postgresql/generic.nix
+++ b/nix/postgresql/generic.nix
@@ -15,7 +15,7 @@ let
       icu75,
       lz4,
       zstd,
-      systemd,
+      systemdLibs,
       libossp_uuid,
       pkg-config,
       libxml2,
@@ -33,7 +33,8 @@ let
       libxslt,
 
       # This is important to obtain a version of `libpq` that does not depend on systemd.
-      systemdSupport ? lib.meta.availableOn stdenv.hostPlatform systemd && !stdenv.hostPlatform.isStatic,
+      systemdSupport ?
+        lib.meta.availableOn stdenv.hostPlatform systemdLibs && !stdenv.hostPlatform.isStatic,
       enableSystemd ? null,
       gssSupport ? with stdenv.hostPlatform; !isWindows && !isStatic,
 
@@ -120,7 +121,7 @@ let
       ++ lib.optionals (olderThan "13") [ libxcrypt ]
       ++ lib.optionals lz4Enabled [ lz4 ]
       ++ lib.optionals zstdEnabled [ zstd ]
-      ++ lib.optionals systemdSupport' [ systemd ]
+      ++ lib.optionals systemdSupport' [ systemdLibs ]
       ++ lib.optionals pythonSupport [ python3 ]
       ++ lib.optionals gssSupport [ libkrb5 ]
       ++ lib.optionals stdenv.isLinux [ linux-pam ]