diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 8818feb5..e57057e8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -16,13 +16,9 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        os: [ubuntu-22.04]
+        os: [ubuntu-22.04, macos-12]
         py: [311]
         allow-fail: [false]
-        include:
-          - os: macos-12
-            py: 311
-            allow-fail: true
 
     steps:
       - uses: actions/checkout@v3.5.3
diff --git a/client_side_tests/test_fetch_content_recompile.sh b/client_side_tests/test_fetch_content_recompile.sh
index f6f13c71..c36785d1 100755
--- a/client_side_tests/test_fetch_content_recompile.sh
+++ b/client_side_tests/test_fetch_content_recompile.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+set -e
 
 tmp_dir=$(mktemp -d -t nain4-recompile-XXXXXX)
 test_dir=$(dirname "$(readlink -f "$0")")
diff --git a/flake.nix b/flake.nix
index fb26f92f..0b55ad60 100644
--- a/flake.nix
+++ b/flake.nix
@@ -22,29 +22,51 @@
           enableRaytracerX11   = false;
         });
 
+        # Should be able to remove this, once https://github.com/NixOS/nixpkgs/issues/234710 is merged
+        clang_16 = if pkgs.stdenv.isDarwin
+          then pkgs.llvmPackages_16.clang.override rec {
+            libc = pkgs.darwin.Libsystem;
+            bintools = pkgs.bintools.override { inherit libc; };
+            inherit (pkgs.llvmPackages) libcxx;
+            extraPackages = [
+              pkgs.llvmPackages.libcxxabi
+              # Use the compiler-rt associated with clang, but use the libc++abi from the stdenv
+              # to avoid linking against two different versions (for the same reasons as above).
+              (pkgs.llvmPackages_16.compiler-rt.override {
+                inherit (pkgs.llvmPackages) libcxxabi;
+              })
+            ];
+          }
+          else pkgs.llvmPackages.clang;
+
+        my-packages = with pkgs; [
+          my-geant4
+          geant4.data.G4PhotonEvaporation
+          geant4.data.G4EMLOW
+          geant4.data.G4RadioactiveDecay
+          geant4.data.G4ENSDFSTATE
+          geant4.data.G4SAIDDATA
+          geant4.data.G4PARTICLEXS
+          geant4.data.G4NDL
+          clang_16
+          clang-tools
+          cmake
+          cmake-language-server
+          catch2_3
+          just
+          gnused # For hacking CMAKE_EXPORT stuff into CMakeLists.txt
+          mdbook
+        ] ++ lib.optionals stdenv.isDarwin [
+
+        ] ++ lib.optionals stdenv.isLinux [
+        ];
+
       in {
 
         devShell = pkgs.mkShell.override { stdenv = pkgs.clang_16.stdenv; } {
           name = "G4-examples-devenv";
 
-          packages = with pkgs; [
-            my-geant4
-            geant4.data.G4PhotonEvaporation
-            geant4.data.G4EMLOW
-            geant4.data.G4RadioactiveDecay
-            geant4.data.G4ENSDFSTATE
-            geant4.data.G4SAIDDATA
-            geant4.data.G4PARTICLEXS
-            geant4.data.G4NDL
-            clang_16
-            clang-tools
-            cmake
-            cmake-language-server
-            catch2_3
-            just
-            gnused # For hacking CMAKE_EXPORT stuff into CMakeLists.txt
-            mdbook
-          ];
+          packages = my-packages;
 
           G4_DIR = "${pkgs.geant4}";
           G4_EXAMPLES_DIR = "${pkgs.geant4}/share/Geant4-11.0.4/examples/";
diff --git a/nain4/CMakeLists.txt b/nain4/CMakeLists.txt
index a3fa5861..e594b951 100644
--- a/nain4/CMakeLists.txt
+++ b/nain4/CMakeLists.txt
@@ -45,6 +45,10 @@ FILE(GLOB HEADERS ${PROJECT_SOURCE_DIR}/*.hh)
 
 add_library(Nain4 SHARED ${SOURCES} ${HEADERS})
 
+if(APPLE)
+    target_link_options(Nain4 PRIVATE -undefined dynamic_lookup)
+endif()
+
 #set_target_properties(Nain4 PROPERTIES ENABLE_EXPORTS ON)
 
 #----------------------------------------------------------------------------
@@ -80,6 +84,10 @@ set(ALL_TEST_SOURCES
 # TODO including headers in add_executable apparently makes them show up in IDEs. Verify how?
 add_executable(nain4-tests ${ALL_TEST_SOURCES})
 
+if(APPLE)
+  target_link_options(nain4-tests PRIVATE -undefined dynamic_lookup)
+endif()
+
 
 target_link_libraries(
   nain4-tests