--- a/keylime/registrar_common.py	2023-07-19 17:26:50.320894695 +0200
+++ b/keylime/registrar_common.py	2023-07-19 17:27:16.797790852 +0200
@@ -456,7 +456,16 @@
                     logger.error("SQLAlchemy Error: %s", e)
                     raise
             else:
-                raise Exception(f"Auth tag {auth_tag} does not match expected value {ex_mac}")
+                if agent_id and session.query(RegistrarMain).filter_by(agent_id=agent_id).delete():
+                    try:
+                        session.commit()
+                    except SQLAlchemyError as e:
+                        logger.error("SQLAlchemy Error: %s", e)
+                        raise
+
+                raise Exception(
+                    f"Auth tag {auth_tag} for agent {agent_id} does not match expected value. The agent has been deleted from database, and a restart of it will be required"
+                )
 
             web_util.echo_json_response(self, 200, "Success")
             logger.info("PUT activated: %s", agent_id)