diff --git a/src/interfaces/libpq/fe-connect.c b/src/interfaces/libpq/fe-connect.c
index 472381f96a9..1a3a6b237a3 100644
--- a/src/interfaces/libpq/fe-connect.c
+++ b/src/interfaces/libpq/fe-connect.c
@@ -2894,6 +2894,7 @@ closePGconn(PGconn *conn)
 										 * absent */
 	conn->asyncStatus = PGASYNC_IDLE;
 	pqClearAsyncResult(conn);	/* deallocate result and curTuple */
+	resetPQExpBuffer(&conn->errorMessage);
 	pg_freeaddrinfo_all(conn->addrlist_family, conn->addrlist);
 	conn->addrlist = NULL;
 	conn->addr_cur = NULL;