diff --git a/swh/storage/tests/test_storage.py b/swh/storage/tests/test_storage.py
--- a/swh/storage/tests/test_storage.py
+++ b/swh/storage/tests/test_storage.py
@@ -42,6 +42,8 @@
 
     def tearDown(self):
         self.reset_storage()
+        if hasattr(self.storage, '_pool') and self.storage._pool:
+            self.storage._pool.closeall()
         super().tearDown()