diff --git a/.github/workflows/nix-ci.yml b/.github/workflows/nix-ci.yml
index b3b98c307..01c37a6a4 100644
--- a/.github/workflows/nix-ci.yml
+++ b/.github/workflows/nix-ci.yml
@@ -5,14 +5,17 @@ name: Test nix-shell
 on:
   push:
     branches:
-      - 'doesnt_exist'
+      - '*'
 
 
 jobs:
   nix-shell:
+    continue-on-error: true
     strategy:
       matrix:
-        os: [macos-latest, ubuntu-latest]
+        os: [ubuntu-latest]
+        # os: [ubuntu-latest, macos-latest]
+      fail-fast: false
     runs-on: ${{ matrix.os }}
 
     steps:
@@ -27,5 +30,10 @@ jobs:
             # Use channel nixos-23.11 for Linux and nixpkgs-23.11-darwin for macOS
           nix_path: nixpkgs=channel:${{ matrix.os == 'macos-latest' && 'nixpkgs-24.05-darwin' || 'nixos-24.05' }}
 
+      - name: Disable incompatible dependency of `nuls2`
+        run: |
+          sed -i.bak '/py-ed25519-bindings/ s/^[[:space:]]*/# /' pyproject.toml
+          rm pyproject.toml.bak
+
       - name: Run tests
-        run: nix-shell --run "hatch run testing:test -- ./src/ ./test/"
+        run: nix-shell --run "hatch run testing:test"
diff --git a/pyproject.toml b/pyproject.toml
index e06b9a39d..414094200 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -31,7 +31,6 @@ dependencies = [
   "aleph-message==0.6.1",
   "aleph-nuls2==0.1",
   "aleph-p2p-client @ git+https://github.com/aleph-im/p2p-service-client-python@cbfebb871db94b2ca580e66104a67cd730c5020c",
-  "aleph-pytezos==3.13.4",
   "asyncpg==0.30",
   "base58>=1.0.3",
   "coincurve==20",
@@ -50,6 +49,7 @@ dependencies = [
   "pycryptodome==3.21.0",                                                                                                  # for libp2p-stubs
   "pymultihash==0.8.2",                                                                                                    # for libp2p-stubs
   "pynacl==1.5",
+  "pytezos-crypto==3.13.4.1",
   "python-dateutil==2.8.2",
   "pytz==2023.3",
   "pyyaml==6.0.1",
@@ -62,7 +62,7 @@ dependencies = [
   "sqlalchemy-utils==0.38.3",
   "substrate-interface==1.7.4",
   "types-aiofiles==23.2.0.20240403",
-  "ujson==5.10.0",                                                                                                            # required by aiocache
+  "ujson==5.10.0",                                                                                                         # required by aiocache
   "urllib3==2.3",
   "uvloop==0.21",
   "web3==6.11.2",
diff --git a/shell.nix b/shell.nix
index 611230b33..fc57e1ecb 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,6 +1,6 @@
-{ pkgs ? import <nixpkgs> {} }:
+{ }:
 let
-  unstable = import (fetchTarball https://nixos.org/channels/nixos-unstable/nixexprs.tar.xz) {};
+  pkgs = import (fetchTarball "https://nixos.org/channels/nixos-24.11/nixexprs.tar.xz") {};
 in
 pkgs.mkShell {
   buildInputs = [
@@ -8,21 +8,23 @@ pkgs.mkShell {
     pkgs.libiconv  # for macos
 
     pkgs.ps
-    unstable.libsodium
 
     pkgs.postgresql
+    pkgs.postgresql.lib
     pkgs.redis
     pkgs.kubo
-    unstable.hatch
+    pkgs.hatch
     pkgs.rustup
 
-    unstable.python312
-    unstable.python312Packages.virtualenv
-    unstable.python312Packages.pip
-    unstable.python312Packages.setuptools
+    pkgs.python312
+    pkgs.python312Packages.virtualenv
+    pkgs.python312Packages.pip
+    pkgs.python312Packages.setuptools
+    pkgs.python312Packages.distutils
 
-    unstable.python312Packages.fastecdsa
-    unstable.python312Packages.greenlet
+    pkgs.python312Packages.fastecdsa
+    pkgs.python312Packages.libnacl
+    pkgs.python312Packages.greenlet
   ];
 
   shellHook = ''
@@ -65,13 +67,13 @@ pkgs.mkShell {
     fi
 
     # Install the required Python packages
-    ./venv/bin/pip install -e .\[testing\]
+    ./venv/bin/pip install -e ".[testing]"
 
     # PyO3 requires a nightly or dev version of Rust.
     rustup default nightly
 
     # If config.yml does not exist, create it with the port specified in this shell. 
-    [ -e config.yml ] || echo -e "postgres:\n  port: $PG_PORT" > config.yml
+    echo -e "postgres:\n  host: "localhost"\n  port: $PG_PORT" > config.yml
 
     # bold
     echo -e "\e[1m"
@@ -88,5 +90,8 @@ pkgs.mkShell {
 
     # Activate the virtual environment
     source venv/bin/activate
+
+    # Ensure libpq.so.5 can be found. 
+    export LD_LIBRARY_PATH=${pkgs.postgresql.lib}/lib:$LD_LIBRARY_PATH
   '';
 }
diff --git a/src/aleph/chains/tezos.py b/src/aleph/chains/tezos.py
index 59f5690a2..b8a951d8b 100644
--- a/src/aleph/chains/tezos.py
+++ b/src/aleph/chains/tezos.py
@@ -6,9 +6,9 @@
 
 import aiohttp
 from aleph_message.models import Chain
-from aleph_pytezos.crypto.key import Key
 from configmanager import Config
 from nacl.exceptions import BadSignatureError
+from pytezos_crypto.key import Key
 
 import aleph.toolkit.json as aleph_json
 from aleph.chains.abc import ChainReader, Verifier