diff --git a/lib/dns/Makefile.am b/lib/dns/Makefile.am
index e4b397b6f3..d16dd51764 100644
--- a/lib/dns/Makefile.am
+++ b/lib/dns/Makefile.am
@@ -126,7 +126,6 @@ libdns_la_HEADERS =			\
 	include/dns/ssu.h		\
 	include/dns/stats.h		\
 	include/dns/time.h		\
-	include/dns/timer.h		\
 	include/dns/transport.h		\
 	include/dns/tkey.h		\
 	include/dns/tsec.h		\
@@ -230,7 +229,6 @@ libdns_la_SOURCES =			\
 	ssu_external.c			\
 	stats.c				\
 	time.c				\
-	timer.c				\
 	transport.c			\
 	tkey.c				\
 	tsec.c				\
diff --git a/lib/dns/include/dns/timer.h b/lib/dns/include/dns/timer.h
deleted file mode 100644
index 2382c52f5d..0000000000
--- a/lib/dns/include/dns/timer.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
- *
- * SPDX-License-Identifier: MPL-2.0
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, you can obtain one at https://mozilla.org/MPL/2.0/.
- *
- * See the COPYRIGHT file distributed with this work for additional
- * information regarding copyright ownership.
- */
-
-#pragma once
-
-/*! \file dns/timer.h */
-
-/***
- ***	Imports
- ***/
-
-#include <stdbool.h>
-
-#include <isc/buffer.h>
-#include <isc/lang.h>
-
-ISC_LANG_BEGINDECLS
-
-/***
- ***	Functions
- ***/
-
-isc_result_t
-dns_timer_setidle(isc_timer_t *timer, unsigned int maxtime,
-		  unsigned int idletime, bool purge);
-/*%<
- * Convenience function for setting up simple, one-second-granularity
- * idle timers as used by zone transfers.
- * \brief
- * Set the timer 'timer' to go off after 'idletime' seconds of inactivity,
- * or after 'maxtime' at the very latest.  Events are purged iff
- * 'purge' is true.
- */
-
-ISC_LANG_ENDDECLS
diff --git a/lib/dns/timer.c b/lib/dns/timer.c
deleted file mode 100644
index ef2895d4e5..0000000000
--- a/lib/dns/timer.c
+++ /dev/null
@@ -1,54 +0,0 @@
-/*
- * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
- *
- * SPDX-License-Identifier: MPL-2.0
- *
- * This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, you can obtain one at https://mozilla.org/MPL/2.0/.
- *
- * See the COPYRIGHT file distributed with this work for additional
- * information regarding copyright ownership.
- */
-
-/*! \file */
-
-#include <stdbool.h>
-
-#include <isc/result.h>
-#include <isc/time.h>
-#include <isc/timer.h>
-
-#include <dns/timer.h>
-#include <dns/types.h>
-
-#define CHECK(op)                            \
-	do {                                 \
-		result = (op);               \
-		if (result != ISC_R_SUCCESS) \
-			goto failure;        \
-	} while (0)
-
-isc_result_t
-dns_timer_setidle(isc_timer_t *timer, unsigned int maxtime,
-		  unsigned int idletime, bool purge) {
-	isc_result_t result;
-	isc_interval_t maxinterval, idleinterval;
-	isc_time_t expires;
-
-	/* Compute the time of expiry. */
-	isc_interval_set(&maxinterval, maxtime, 0);
-	CHECK(isc_time_nowplusinterval(&expires, &maxinterval));
-
-	/*
-	 * Compute the idle interval, and add a spare nanosecond to
-	 * work around the silly limitation of the ISC timer interface
-	 * that you cannot specify an idle interval of zero.
-	 */
-	isc_interval_set(&idleinterval, idletime, 1);
-
-	CHECK(isc_timer_reset(timer, isc_timertype_once, &expires,
-			      &idleinterval, purge));
-failure:
-	return (result);
-}