diff --git a/Tests/test_fault.py b/Tests/test_fault.py
index 8eb8944..5ce8f05 100644
--- a/Tests/test_fault.py
+++ b/Tests/test_fault.py
@@ -10,7 +10,7 @@ def run(label, steps):
         if step[0] == "nl2bench":
             cmd = step
         else:
-            cmd = ["swift", "run", "fault"] + step
+            cmd = shlex.split(os.getenv("PYTEST_FAULT_BIN", "swift run Fault")) + step
         print(f"$ {shlex.join(cmd)}")
         subprocess.check_call(cmd)
 
diff --git a/default.nix b/default.nix
index 7426384..1f0997a 100644
--- a/default.nix
+++ b/default.nix
@@ -23,7 +23,6 @@ stdenv.mkDerivation (finalAttrs: {
 	
 	src = nix-gitignore.gitignoreSourcePure ./.gitignore ./.;
   
-  nativeBuildInputs = [ swift swiftpm makeBinaryWrapper ];
 	swiftpmFlags = [
     "--verbose"
   ];
@@ -39,6 +38,12 @@ stdenv.mkDerivation (finalAttrs: {
   #   "-Xswiftc"
   #   "x86_64-apple-macosx11"
   # ];
+  nativeBuildInputs = [ swift swiftpm makeBinaryWrapper ];
+  
+  buildInputs = with swiftPackages; [
+    Foundation
+    XCTest
+  ] ++ lib.lists.optional (!stdenv.isDarwin) [Dispatch];
   
   propagatedBuildInputs = [
     pyenv
@@ -48,10 +53,9 @@ stdenv.mkDerivation (finalAttrs: {
     nl2bench
   ];
   
-  buildInputs = with swiftPackages; [
-    Foundation
-    XCTest
-  ] ++ lib.lists.optional (!stdenv.isDarwin) [Dispatch];
+  nativeCheckInputs = with python3.pkgs; [
+    pytest
+  ];
   
   configurePhase = generated.configure;
 
@@ -66,9 +70,9 @@ stdenv.mkDerivation (finalAttrs: {
     export LD_LIBRARY_PATH=${swiftPackages.Dispatch}/lib:$LD_LIBRARY_PATH
   '';
   
-  doCheck = !swiftPackages.stdenv.isDarwin;
+  doCheck = true;
   
-  preCheck = ''
+  faultEnv = ''
     export PYTHONPATH=${pyenv}/${pyenv.sitePackages}
     export PATH=${verilog}/bin:$PATH
     export PATH=${yosys}/bin:$PATH
@@ -77,9 +81,8 @@ stdenv.mkDerivation (finalAttrs: {
   '';
   
   checkPhase = ''
-    ${finalAttrs.preCheck}
-    echo $PATH
-    swift test
+    ${finalAttrs.faultEnv}
+    PYTEST_FAULT_BIN="$(swiftpmBinPath)/fault" pytest
   '';
   
   fixupPhase = ''
@@ -98,5 +101,5 @@ stdenv.mkDerivation (finalAttrs: {
     platforms = platforms.linux ++ platforms.darwin;
   };
   
-  shellHook = finalAttrs.preCheck + finalAttrs.preBuild;
+  shellHook = finalAttrs.faultEnv + finalAttrs.preBuild;
 })
diff --git a/flake.lock b/flake.lock
index 39efd17..410a1eb 100644
--- a/flake.lock
+++ b/flake.lock
@@ -177,15 +177,16 @@
         ]
       },
       "locked": {
-        "lastModified": 1721137344,
-        "narHash": "sha256-ZRWbrI+HCpTZAbgTjqf4IWMuUspk++DI4DGeVTBNumQ=",
-        "owner": "coloquinte",
+        "lastModified": 1722000917,
+        "narHash": "sha256-OcvZO3l8CyjGpfIoR0nAMKqUQu8FPwY1dNX2vqopvrk=",
+        "owner": "donn",
         "repo": "quaigh",
-        "rev": "1b690ebece60a0181df7af22546f13427914cf82",
+        "rev": "cfad5cae30496b1ad49e58118d4649e2aac20935",
         "type": "github"
       },
       "original": {
-        "owner": "coloquinte",
+        "owner": "donn",
+        "ref": "fix_nix_linux",
         "repo": "quaigh",
         "type": "github"
       }
diff --git a/flake.nix b/flake.nix
index 5dc6505..3d4fe39 100644
--- a/flake.nix
+++ b/flake.nix
@@ -3,7 +3,7 @@
     nix-eda.url = github:efabless/nix-eda;
     nl2bench.url = github:donn/nl2bench;
     quaigh = {
-      url = github:coloquinte/quaigh;
+      url = github:donn/quaigh/fix_nix_linux;
       inputs.nixpkgs.follows = "nix-eda/nixpkgs";
     };
   };