diff --git a/tests/test_files.py b/tests/test_files.py
index 309d261..538542a 100644
--- a/tests/test_files.py
+++ b/tests/test_files.py
@@ -202,6 +202,11 @@ def fake_run(args, **kwargs):
 
     assert result["action"] == "reveal_in_finder"
     assert seen["args"][0] == "osascript"
+    # Finder's `reveal` needs an alias/file reference; a bare `POSIX file`
+    # specifier raises -1728 ("Can't get POSIX file ..."). Ensure we coerce.
+    script = " ".join(seen["args"])
+    assert "as alias" in script
+    assert "reveal POSIX file (item 1 of argv)" not in script
 
 
 def test_get_finder_selection_parses_alias_output(monkeypatch):
diff --git a/tools/files.py b/tools/files.py
index a71069a..ff82116 100644
--- a/tools/files.py
+++ b/tools/files.py
@@ -470,7 +470,7 @@ def reveal_in_finder(path: str) -> str:
         script = (
             'on run argv\n'
             '  tell application "Finder"\n'
-            '    reveal POSIX file (item 1 of argv)\n'
+            '    reveal (POSIX file (item 1 of argv) as alias)\n'
             "    activate\n"
             "  end tell\n"
             "end run\n"