diff --git a/.github/workflows/test-nix.yml b/.github/workflows/test-nix.yml
index e63af3e..a49dda7 100644
--- a/.github/workflows/test-nix.yml
+++ b/.github/workflows/test-nix.yml
@@ -29,7 +29,6 @@ jobs:
           CACHIX_AUTH_TOKEN: "${{ secrets.CACHIX_TOKEN_HOLOCHAIN_OPEN_DEV }}"
         run: |
           cd ./nix/fixture
-          yes | nix flake update
           cachix watch-exec holochain-open-dev -- nix build -L .#my_zome.meta.debug
           cachix watch-exec holochain-open-dev -- nix build -L .#my_zome
           sha256sum result
@@ -51,6 +50,10 @@ jobs:
         with:
           name: holochain-ci
 
+      - uses: cachix/cachix-action@v10
+        with:
+          name: holochain-open-dev
+
       - name: Install coreutils for macOS
         if: matrix.os == 'macos-latest'
         run: brew install coreutils
@@ -58,7 +61,6 @@ jobs:
       - name: Build zomes
         run: |
           cd ./nix/fixture
-          yes | nix flake update
           nix build -L .#my_zome.meta.debug
           nix build -L .#my_zome
           sha256sum result
diff --git a/flake.nix b/flake.nix
index 24c5e9e..e54c8b4 100644
--- a/flake.nix
+++ b/flake.nix
@@ -42,9 +42,24 @@
 						filterDnas = filterByHolochainPackageType "dna";
 						filterHapps = filterByHolochainPackageType "happ";
 
-						rustZome = { crateCargoToml,  workspacePath, excludedCrates ? [] }: 
+						rustZome = { crateCargoToml, holochain,  workspacePath, excludedCrates ? [] }: 
 							let 
-							  system = "x86_64-linux";
+							  deterministicCraneLib = let 
+									system = "x86_64-linux";
+								  pkgs = import inputs.nixpkgs {
+								    inherit system;
+								    overlays = [ (import inputs.rust-overlay) ];
+								  };
+
+								  rustToolchain = pkgs.rust-bin.nightly."2024-01-29".minimal.override {
+								    # Set the build targets supported by the toolchain,
+								    # wasm32-unknown-unknown is required for trunk.
+								    targets = [ "wasm32-unknown-unknown" ];
+								  };
+								in
+					        inputs.crane.lib.${system}.overrideToolchain rustToolchain;
+
+							  system = holochain.legacyPackages.cowsay.system;
 							  pkgs = import inputs.nixpkgs {
 							    inherit system;
 							    overlays = [ (import inputs.rust-overlay) ];
@@ -59,7 +74,7 @@
 
 							in
 								pkgs.callPackage ./nix/zome.nix {
-					        inherit craneLib crateCargoToml excludedCrates workspacePath;
+					        inherit deterministicCraneLib craneLib crateCargoToml excludedCrates workspacePath;
 								};
 						sweettest = { holochain, dna, workspacePath, crateCargoToml }: 
 						  let
diff --git a/nix/fixture/flake.lock b/nix/fixture/flake.lock
index 311d500..fd64eef 100644
--- a/nix/fixture/flake.lock
+++ b/nix/fixture/flake.lock
@@ -717,7 +717,7 @@
       },
       "locked": {
         "lastModified": 0,
-        "narHash": "sha256-WXZBLFHhN58QcK1zogs8LA+LmQeCSz3Uo1XsTvwLMio=",
+        "narHash": "sha256-tGdMa5qZOHvnpo3VE55aW/37bxlMUHsvNsFz6uoxKtU=",
         "path": "../..",
         "type": "path"
       },
diff --git a/nix/fixture/zome/zome.nix b/nix/fixture/zome/zome.nix
index 16afb09..b40a1ab 100644
--- a/nix/fixture/zome/zome.nix
+++ b/nix/fixture/zome/zome.nix
@@ -8,6 +8,7 @@
     }: {
       packages.my_zome = inputs.hcUtils.outputs.lib.rustZome {
         workspacePath = rootPath;
+        holochain = inputs'.holochain;
 				crateCargoToml = ./Cargo.toml;
       };
       checks.my_zome = inputs.hcUtils.outputs.lib.sweettest {
diff --git a/nix/zome.nix b/nix/zome.nix
index 7447071..1c1e476 100644
--- a/nix/zome.nix
+++ b/nix/zome.nix
@@ -2,7 +2,7 @@
 	runCommandLocal,
 	runCommandNoCC,
 	binaryen,
-	callPackage,
+  deterministicCraneLib,
   craneLib,
   workspacePath,
 	crateCargoToml,
@@ -31,7 +31,7 @@ let
 		cargoToml = crateCargoToml;
 		cargoLock = workspacePath + /Cargo.lock;
 		cargoArtifacts = wasmDeps;
-		cargoExtraArgs = "-p ${crate} --locked -v";
+		cargoExtraArgs = "-p ${crate} --locked";
 	  pname = crate;
 		version = cargoToml.package.version;
 	});
@@ -42,14 +42,31 @@ let
 	} ''
 		cp ${wasm}/lib/${crate}.wasm $out 
 	'';
+
+	deterministicWasm = 
+	let 
+	  wasmDeps = deterministicCraneLib.buildDepsOnly (commonArgs // {
+			inherit cargoExtraArgs;
+			pname = "happ-workspace";
+			version = "workspace";
+		});
+		wasm = deterministicCraneLib.buildPackage (commonArgs // {
+			cargoToml = crateCargoToml;
+			cargoLock = workspacePath + /Cargo.lock;
+			cargoArtifacts = wasmDeps;
+			cargoExtraArgs = "-p ${crate} --locked";
+		  pname = crate;
+			version = cargoToml.package.version;
+		});
+	in
+		runCommandLocal "${crate}-deterministic" {
+			meta = {
+				holochainPackageType = "zome";
+			};
+		} ''
+			cp ${wasm}/lib/${crate}.wasm $out 
+		'';
 in
- #  callPackage ./deterministic-zome.nix {
- #    inherit workspacePath crateCargoToml;
-	# 	meta = {
-	# 		inherit debug;
-	# 		holochainPackageType = "zome";
-	# 	};
-	# }
 	runCommandNoCC crate {
 		meta = {
 			inherit debug;
@@ -57,5 +74,5 @@ in
 		};
 		buildInputs = [ binaryen ];
 	} ''
-	  wasm-opt --strip-debug -Oz -o $out ${debug}
+	  wasm-opt --strip-debug -Oz -o $out ${deterministicWasm}
 	''