diff --git a/pkgs/clan-cli/clan_cli/nix.py b/pkgs/clan-cli/clan_cli/nix.py
new file mode 100644
index 000000000..b5515676d
--- /dev/null
+++ b/pkgs/clan-cli/clan_cli/nix.py
@@ -0,0 +1,10 @@
+import os
+
+CLAN_NIXPKGS = os.environ.get("CLAN_NIXPKGS")
+
+
+def nix_shell(packages: list[str], cmd: list[str]) -> list[str]:
+    # in unittest we will have all binaries provided
+    if CLAN_NIXPKGS is None:
+        return cmd
+    return ["nix", "shell", "-f", CLAN_NIXPKGS] + packages + ["-c"] + cmd
diff --git a/pkgs/clan-cli/clan_cli/zerotier/__init__.py b/pkgs/clan-cli/clan_cli/zerotier/__init__.py
index 4f383a885..21210aca1 100644
--- a/pkgs/clan-cli/clan_cli/zerotier/__init__.py
+++ b/pkgs/clan-cli/clan_cli/zerotier/__init__.py
@@ -1,5 +1,4 @@
 import json
-import os
 import socket
 import subprocess
 import time
@@ -9,6 +8,8 @@ from pathlib import Path
 from tempfile import TemporaryDirectory
 from typing import Any, Iterator, Optional
 
+from ..nix import nix_shell
+
 
 def try_bind_port(port: int) -> bool:
     tcp = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
@@ -36,16 +37,6 @@ def find_free_port(port_range: range) -> int:
     raise Exception("cannot find a free port")
 
 
-CLAN_NIXPKGS = os.environ.get("CLAN_NIXPKGS")
-
-
-def nix_shell(packages: list[str], cmd: list[str]) -> list[str]:
-    # in unittest we will have all binaries provided
-    if CLAN_NIXPKGS is None:
-        return cmd
-    return ["nix", "shell", "-f", CLAN_NIXPKGS] + packages + ["-c"] + cmd
-
-
 class ZerotierController:
     def __init__(self, port: int, home: Path) -> None:
         self.port = port