return
             else:
                 raise NotFoundException(f'Unknown page: /{site}')
-            conn.close()
             self._send_html(html)
         except HandledException as error:
             self._send_msg(error, code=error.http_code)
+        finally:
+            conn.close()
 
     def do_GET_calendar(self, conn: DatabaseConnection,
                         params: ParamsParser) -> str:
             else:
                 msg = f'Page not known as POST target: /{site}'
                 raise NotFoundException(msg)
-            conn.close()
             self._redirect('/')
         except HandledException as error:
             self._send_msg(error, code=error.http_code)
+        finally:
+            conn.close()
 
     def do_POST_day(self, conn: DatabaseConnection, params: ParamsParser,
                     form_data: PostvarsParser) -> None: