diff --git a/features/sandbox_dirs_cache.feature b/features/sandbox_dirs_cache.feature
index fc5c0eae5..0f785fed0 100644
--- a/features/sandbox_dirs_cache.feature
+++ b/features/sandbox_dirs_cache.feature
@@ -38,18 +38,18 @@ Feature: Sandbox directories cache tracking and invalidation (#7527)
   Scenario: Check membership for recorded path
     Given a sandbox dirs cache with one path "/tmp/sandboxes/abc" for plan "plan-check"
     When I check if dir "/tmp/sandboxes/abc" belongs to plan "plan-check"
-    Then the result should be True
+    Then the dir membership result should be True
 
   Scenario: Check membership for non-recorded path returns False
     Given a sandbox dirs cache with one path "/tmp/sandboxes/xyz" for plan "plan-wrong"
     When I check if dir "/tmp/sandboxes/missing" belongs to plan "plan-wrong"
-    Then the result should be False
+    Then the dir membership result should be False
 
   Scenario: Check membership after purge returns False
     Given a sandbox dirs cache with one path "/tmp/sandboxes/cached-dir" for plan "plan-expired"
     When I purge sandbox dirs for plan "plan-expired"
     And I check if dir "/tmp/sandboxes/cached-dir" belongs to plan "plan-expired"
-    Then the result should be False
+    Then the dir membership result should be False
 
   Scenario: Clear all entries empties the cache
     Given a sandbox dirs cache with paths for plans "plan-clear-1" and "plan-clear-2"
diff --git a/features/steps/sandbox_dirs_cache_steps.py b/features/steps/sandbox_dirs_cache_steps.py
index 814d10946..36c0bf602 100644
--- a/features/steps/sandbox_dirs_cache_steps.py
+++ b/features/steps/sandbox_dirs_cache_steps.py
@@ -20,17 +20,13 @@ def step_given_empty_cache(context):
     context._sdc = SandboxDirsCache()
 
 
-@given(
-    'a sandbox dirs cache with one path "{dir_path}" for plan "{plan_id}"'
-)
+@given('a sandbox dirs cache with one path "{dir_path}" for plan "{plan_id}"')
 def step_given_one_dir(context, dir_path, plan_id):
     context._sdc = SandboxDirsCache()
     context._sdc.record(plan_id, dir_path)
 
 
-@given(
-    'a sandbox dirs cache with paths for plans "{plan_a}" and "{plan_b}"'
-)
+@given('a sandbox dirs cache with paths for plans "{plan_a}" and "{plan_b}"')
 def step_given_two_plans(context, plan_a, plan_b):
     context._sdc = SandboxDirsCache()
     context._sdc.record(plan_a, f"/tmp/sandboxes/{plan_a}-dir")
@@ -117,12 +113,12 @@ def step_then_no_plans_removed(context):
     assert context._sdc.plan_count == 0
 
 
-@then("the result should be True")
+@then("the dir membership result should be True")
 def step_then_membership_true(context):
     assert context._check_result is True
 
 
-@then("the result should be False")
+@then("the dir membership result should be False")
 def step_then_membership_false(context):
     assert context._check_result is False
 
diff --git a/src/cleveragents/application/services/cleanup_service.py b/src/cleveragents/application/services/cleanup_service.py
index 3aff5501c..8d7a33432 100644
--- a/src/cleveragents/application/services/cleanup_service.py
+++ b/src/cleveragents/application/services/cleanup_service.py
@@ -191,6 +191,7 @@ class CleanupService:
                     report.sandboxes.removed += 1
                 except OSError:
                     report.sandboxes.skipped += 1
+        self._sandbox_dirs_cache = None
 
     # ── Checkpoint cleanup ────────────────────────────────────────
 
diff --git a/src/cleveragents/infrastructure/sandbox/dirs_cache.py b/src/cleveragents/infrastructure/sandbox/dirs_cache.py
index 6fbd7335e..b0d8c7108 100644
--- a/src/cleveragents/infrastructure/sandbox/dirs_cache.py
+++ b/src/cleveragents/infrastructure/sandbox/dirs_cache.py
@@ -12,7 +12,6 @@ from __future__ import annotations
 
 import logging
 import threading
-from typing import Any
 
 logger = logging.getLogger(__name__)
 
@@ -87,9 +86,7 @@ class SandboxDirsCache:
             removed = list(self._dirs.pop(plan_id, set()))
 
         if removed:
-            logger.info(
-                "Purged %d sandbox dir(s) for plan=%s", len(removed), plan_id
-            )
+            logger.info("Purged %d sandbox dir(s) for plan=%s", len(removed), plan_id)
 
         return removed