diff --git a/backend/tests/test_env_paths.py b/backend/tests/test_env_paths.py
index 372c29957..2eb4529c0 100644
--- a/backend/tests/test_env_paths.py
+++ b/backend/tests/test_env_paths.py
@@ -2,7 +2,12 @@
 
 import pytest
 
-from core.env_paths import expand_operator_path, operator_home
+from core.env_paths import (
+    ENV_FILE_PATHS,
+    expand_operator_path,
+    operator_env_file_paths,
+    operator_home,
+)
 
 
 def test_operator_home_resolves_home_override(monkeypatch, tmp_path: Path) -> None:
@@ -32,3 +37,26 @@ def test_expand_operator_path_rejects_home_escape(monkeypatch, tmp_path: Path) -
 
     with pytest.raises(ValueError, match="escapes"):
         expand_operator_path("~/../outside.env")
+
+
+def test_operator_env_file_paths_default(monkeypatch, tmp_path: Path) -> None:
+    home = tmp_path / "home"
+    home.mkdir()
+    monkeypatch.setenv("HOME", str(home))
+
+    paths = operator_env_file_paths()
+
+    assert paths == tuple(str(expand_operator_path(path)) for path in ENV_FILE_PATHS)
+    assert str(home.resolve() / ".env") in paths
+
+
+def test_operator_env_file_paths_custom(monkeypatch, tmp_path: Path) -> None:
+    home = tmp_path / "home"
+    home.mkdir()
+    monkeypatch.setenv("HOME", str(home))
+
+    assert operator_env_file_paths(("~/.env.custom", "local.env", "~")) == (
+        str(home.resolve() / ".env.custom"),
+        "local.env",
+        str(home.resolve()),
+    )