diff --git a/src/contextsafe/diagnostics.py b/src/contextsafe/diagnostics.py
index dd36cc8..8096e79 100644
--- a/src/contextsafe/diagnostics.py
+++ b/src/contextsafe/diagnostics.py
@@ -34,6 +34,7 @@
 
 from __future__ import annotations
 
+import errno
 import os
 import platform
 import sys
@@ -231,9 +232,13 @@ def remove_cleanup(plan: CleanupPlan) -> tuple[int, int]:
             # deleting the thing we just declined to delete.
             try:
                 target.rmdir()
-            except OSError:
-                retained += 1
-                continue
+            except OSError as exc:
+                if exc.errno in (errno.ENOTEMPTY, errno.EEXIST):
+                    retained += 1
+                    continue
+                raise ContextSafeError(
+                    "cleanup_io_error", "$", "a workspace entry could not be removed"
+                ) from exc
         else:
             try:
                 target.unlink()
diff --git a/tests/test_diagnostics.py b/tests/test_diagnostics.py
index 864ce30..8dada83 100644
--- a/tests/test_diagnostics.py
+++ b/tests/test_diagnostics.py
@@ -16,6 +16,7 @@
 
 from __future__ import annotations
 
+import errno
 import json
 import os
 import unicodedata
@@ -549,6 +550,21 @@ def refuse(self: Path, *args: Any, **kwargs: Any) -> None:
     assert excinfo.value.code == "cleanup_io_error"
 
 
+def test_removal_reports_a_directory_it_cannot_delete_for_non_empty_error(
+    monkeypatch: pytest.MonkeyPatch, populated_workspace: Path
+) -> None:
+    """A directory rmdir failure from permission/IO error raises cleanup_io_error."""
+
+    def refuse(self: Path, *args: Any, **kwargs: Any) -> None:
+        raise PermissionError(errno.EACCES, "Permission denied")
+
+    plan = enumerate_cleanup(populated_workspace)
+    monkeypatch.setattr(Path, "rmdir", refuse)
+    with pytest.raises(ContextSafeError) as excinfo:
+        remove_cleanup(plan)
+    assert excinfo.value.code == "cleanup_io_error"
+
+
 def test_an_unreadable_log_is_reported_not_overwritten(
     monkeypatch: pytest.MonkeyPatch, tmp_path: Path
 ) -> None: