diff --git a/.ci/build_nix.sh b/.ci/build_nix.sh
new file mode 100755
index 0000000000..b174bb0125
--- /dev/null
+++ b/.ci/build_nix.sh
@@ -0,0 +1,8 @@
+#!/bin/sh
+
+set -u
+
+nix \
+  --extra-experimental-features nix-command \
+  --extra-experimental-features flakes \
+  build -j$THREADS --log-format raw --max-silent-time 3600 "$@"
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index 1081410b4f..34d41c4e16 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -73,8 +73,21 @@ nix-build:
   stage: test
   before_script:
    - nix-env -i gawk
+   - export THREADS=$(./.ci/effective_cpus.sh)
+   - export
   script:
-    - nix-build -j$(./.ci/effective_cpus.sh) --log-format raw --max-silent-time 3600
+    - .ci/build_nix.sh .#clash-prelude
+    - .ci/build_nix.sh .#clash-prelude-hedgehog
+    - .ci/build_nix.sh .#clash-lib
+    - .ci/build_nix.sh .#clash-lib-hedgehog
+    - .ci/build_nix.sh .#clash-ghc
+    - .ci/build_nix.sh .#clash-cosim
+    - .ci/build_nix.sh .#clash-ffi
+    - .ci/build_nix.sh .#clash-testsuite
+    - .ci/build_nix.sh .#clash-benchmark
+    - .ci/build_nix.sh .#clash-profiling-prepare
+    - .ci/build_nix.sh .#clash-profiling
+    - .ci/build_nix.sh .#clash-term
   tags:
     - local
 
diff --git a/nix/overlay-ghc910.nix b/nix/overlay-ghc910.nix
new file mode 100644
index 0000000000..19815b2674
--- /dev/null
+++ b/nix/overlay-ghc910.nix
@@ -0,0 +1,71 @@
+{ pkgs }:
+final: prev:
+let
+  inherit (pkgs.haskell.lib) dontCheck doJailbreak markUnbroken;
+in
+{
+  # Use an older version than the default in nixpkgs. Since rewrite-inspector
+  # is basically abandonware it catches fire with brick 1.0+.
+  brick = doJailbreak prev.brick_0_70_1;
+
+  # brick 0.70.1 requires vty < 6.0.
+  vty = doJailbreak (prev.callHackage "vty" "5.39" { });
+
+  # Relies on older versions of some libraries.
+  hint = doJailbreak prev.hint;
+
+  # Marked as broken in nixpkgs, since it specifies much older dependencies
+  # than the defaults in nixpkgs.
+  rewrite-inspector = doJailbreak (markUnbroken prev.rewrite-inspector);
+
+  # Requires some old versions of libraries, but still works.
+  derive-storable-plugin = doJailbreak prev.derive-storable-plugin;
+
+  # Marken as broken, but compiles anyway.
+  hedgehog-fakedata = doJailbreak (markUnbroken prev.hedgehog-fakedata);
+
+  # Fails on GHC 9.10 with:
+  #   library/Text/Regex/PCRE/Heavy.hs:123: failure in expression `head $ scan [re|\s*entry (\d+) (\w+)\s*&?|] (" entry 1 hello  &entry 2 hi" :: String)'
+  # expected: (" entry 1 hello  &",["1","hello"])
+  #  but got: <interactive>:55:1: warning: [GHC-63394] [-Wx-partial]
+  #           ^
+  #               In the use of ‘head’
+  #               (imported from Prelude.Compat, but defined in GHC.Internal.List):
+  #               "This is a partial function, it throws an error on empty lists. Use pattern matching, 'Data.List.uncons' or 'Data.Maybe.listToMaybe' instead. Consider refactoring to use "Data.List.NonEmpty"."
+  # (" entry 1 hello  &",["1","hello"])
+
+  pcre-heavy = dontCheck prev.pcre-heavy;
+
+  # Relies on older versions of text.
+  string-random = doJailbreak prev.string-random;
+
+  # We need the newest version from nixpkgs for these packages.
+  singletons-base = prev.singletons-base_3_4;
+
+  microstache = prev.microstache_1_0_3;
+
+  th-desugar = prev.th-desugar_1_17;
+
+  # We need a new tasty-flaky. The one from Hackage doesn't build for some weird
+  # reason..
+  tasty-flaky = prev.callCabal2nix "tasty-flaky" (pkgs.fetchFromGitHub {
+    owner = "LaurentRDC";
+    repo  = "tasty-flaky";
+    rev = "fc31a9d622c1eb60030a50152258a9bef785e365";
+    sha256 = "sha256-irLM3aVMxpBgsM72ArulMXcoLY2glalVkG//Lrj2JBI=";
+  }) {};
+
+  tasty = prev.tasty_1_5;
+
+  singletons-th = prev.singletons-th_3_4;
+
+  # nixplgs doesn't include revision 1, changing dependency on template-haskell.
+  string-interpolate = pkgs.haskell.lib.compose.overrideCabal (drv: {
+    revision = "1";
+    editedCabalFile = "sha256-oh0tR+LDFcVzQnm4kSrmhAU+P7wdai536d72Cvhzipg=";
+  }) (prev.callHackageDirect {
+    pkg = "string-interpolate";
+    ver = "0.3.4.0";
+    sha256 = "sha256-KA8P6cc6N7pZ9/ay3edcEGx4vpKtp+EY7tn8U1NrbG8=";
+  } { });
+}