diff --git a/databases.ipynb b/databases.ipynb
index b183959..d22a460 100644
--- a/databases.ipynb
+++ b/databases.ipynb
@@ -233,6 +233,7 @@
     "\n",
     "import os\n",
     "\n",
+    "con_new.close()\n",
     "os.remove(\"data/test_database.sqlite\")"
    ]
   },
@@ -755,6 +756,8 @@
    "source": [
     "# remove-cell\n",
     "\n",
+    "con.close()\n",
+    "engine.dispose()\n",
     "os.remove(\"data/hero.db\")"
    ]
   },