diff --git a/pkgs/clan-cli/clan_cli/config/__init__.py b/pkgs/clan-cli/clan_cli/config/__init__.py
index 79824c5..3dcbc93 100644
--- a/pkgs/clan-cli/clan_cli/config/__init__.py
+++ b/pkgs/clan-cli/clan_cli/config/__init__.py
@@ -92,7 +92,7 @@ def cast(value: Any, type: Type, opt_description: str) -> Any:
 
 
 def process_args(
-    option: str, value: Any, options: dict, option_description: str = ""
+    option: str, value: Any, options: dict, out_file: Path, option_description: str = ""
 ) -> None:
     option_path = option.split(".")
 
@@ -107,6 +107,7 @@ def process_args(
             option=".".join(option_parent),
             value={attr: value},
             options=options,
+            out_file=out_file,
             option_description=option,
         )
 
@@ -125,14 +126,14 @@ def process_args(
     current[option_path[-1]] = casted
 
     # check if there is an existing config file
-    if os.path.exists("clan-settings.json"):
-        with open("clan-settings.json") as f:
+    if os.path.exists(out_file):
+        with open(out_file) as f:
             current_config = json.load(f)
     else:
         current_config = {}
     # merge and save the new config file
     new_config = merge(current_config, result)
-    with open("clan-settings.json", "w") as f:
+    with open(out_file, "w") as f:
         json.dump(new_config, f, indent=2)
     print("New config:")
     print(json.dumps(new_config, indent=2))
@@ -178,10 +179,22 @@ def _register_parser(
     # inject callback function to process the input later
     parser.set_defaults(
         func=lambda args: process_args(
-            option=args.option, value=args.value, options=options
+            option=args.option,
+            value=args.value,
+            options=options,
+            out_file=args.out_file,
         )
     )
 
+    # add argument to pass output file
+    parser.add_argument(
+        "--out-file",
+        "-o",
+        help="Output file",
+        type=Path,
+        default=Path("clan-settings.json"),
+    )
+
     # add single positional argument for the option (e.g. "foo.bar")
     parser.add_argument(
         "option",
diff --git a/pkgs/clan-cli/default.nix b/pkgs/clan-cli/default.nix
index 93f7b53..9939d1b 100644
--- a/pkgs/clan-cli/default.nix
+++ b/pkgs/clan-cli/default.nix
@@ -21,6 +21,10 @@
 , rsync
 }:
 let
+  # This provides dummy options for testing clan config and prevents it from
+  # evaluating the flake .#
+  CLAN_OPTIONS_FILE = ./clan_cli/config/jsonschema/options.json;
+
   dependencies = [ argcomplete ];
 
   testDependencies = [
@@ -48,7 +52,7 @@ python3.pkgs.buildPythonPackage {
   src = source;
   format = "pyproject";
 
-  CLAN_OPTIONS_FILE = ./clan_cli/config/jsonschema/options.json;
+  inherit CLAN_OPTIONS_FILE;
 
   nativeBuildInputs = [
     setuptools
@@ -58,6 +62,7 @@ python3.pkgs.buildPythonPackage {
 
   passthru.tests = {
     clan-mypy = runCommand "clan-mypy" { } ''
+      export CLAN_OPTIONS_FILE="${CLAN_OPTIONS_FILE}"
       cp -r ${source} ./src
       chmod +w -R ./src
       cd ./src
@@ -68,6 +73,7 @@ python3.pkgs.buildPythonPackage {
       {
         nativeBuildInputs = [ age zerotierone bubblewrap sops nix openssh rsync stdenv.cc ];
       } ''
+      export CLAN_OPTIONS_FILE="${CLAN_OPTIONS_FILE}"
       cp -r ${source} ./src
       chmod +w -R ./src
       cd ./src
diff --git a/pkgs/clan-cli/shell.nix b/pkgs/clan-cli/shell.nix
index 61a98ff..1a17315 100644
--- a/pkgs/clan-cli/shell.nix
+++ b/pkgs/clan-cli/shell.nix
@@ -20,6 +20,9 @@ pkgs.mkShell {
   ];
   # sets up an editable install and add enty points to $PATH
   CLAN_FLAKE = self;
+  # This provides dummy options for testing clan config and prevents it from
+  # evaluating the flake .#
+  CLAN_OPTIONS_FILE = ./clan_cli/config/jsonschema/options.json;
   shellHook = ''
     tmp_path=$(realpath ./.pythonenv)
     repo_root=$(realpath .)
diff --git a/pkgs/clan-cli/tests/test_config.py b/pkgs/clan-cli/tests/test_config.py
index 165626d..effba09 100644
--- a/pkgs/clan-cli/tests/test_config.py
+++ b/pkgs/clan-cli/tests/test_config.py
@@ -1,6 +1,7 @@
 import argparse
 import json
 import sys
+import tempfile
 from pathlib import Path
 from typing import Any
 
@@ -32,15 +33,20 @@ def test_set_some_option(
     monkeypatch: pytest.MonkeyPatch,
 ) -> None:
     # monkeypatch sys.argv
-    monkeypatch.setattr(sys, "argv", [""] + argv)
-    parser = argparse.ArgumentParser()
-    config.register_parser(parser=parser, optionsFile=Path(example_options))
-    args = parser.parse_args()
-    args.func(args)
-    captured = capsys.readouterr()
-    print(captured.out)
-    json_out = json.loads(captured.out)
-    assert json_out == expected
+    # create temporary file for out_file
+    with tempfile.NamedTemporaryFile() as out_file:
+        with open(out_file.name, "w") as f:
+            json.dump({}, f)
+        monkeypatch.setattr(sys, "argv", ["", "--out-file", out_file.name] + argv)
+        parser = argparse.ArgumentParser()
+        config._register_parser(
+            parser=parser,
+            options=json.loads(Path(example_options).read_text()),
+        )
+        args = parser.parse_args()
+        args.func(args)
+        json_out = json.loads(open(out_file.name).read())
+        assert json_out == expected
 
 
 def test_walk_jsonschema_all_types() -> None: