diff --git a/tests/test_issue21_loop_b.py b/tests/test_issue21_loop_b.py
index 339e4d5..8ea3dbc 100644
--- a/tests/test_issue21_loop_b.py
+++ b/tests/test_issue21_loop_b.py
@@ -394,6 +394,8 @@ def test_l15_truncated_diff_refuses_diff_only_but_not_local(wt_repo, monkeypatch
     dst.mkdir(parents=True)
     (dst / "diff_collect.sh").write_text(DIFF_SH.read_text())
     (dst.parent.parent / "lib_int.sh").write_text((SKILLS / "lib_int.sh").read_text())  # its integer rule
+    (dst.parent.parent / "lib_py").mkdir()  # Issue #17 item 4: lib_int.sh runs lib_py/ints.py
+    (dst.parent.parent / "lib_py" / "ints.py").write_text((SKILLS / "lib_py" / "ints.py").read_text())
     monkeypatch.setenv("MAM_DIFF_MAX_LINES", "1")
     _state(monkeypatch, LOCAL_ROWS + [REMOTE_ROW])
     argv = ["--worktree", str(wt), "--base", before, "--review-only", "--remote-review", "diff-only"]