diff --git a/lib/isc/include/isc/quota.h b/lib/isc/include/isc/quota.h
index 8ca1fdf6da..6f593c0ba9 100644
--- a/lib/isc/include/isc/quota.h
+++ b/lib/isc/include/isc/quota.h
@@ -40,11 +40,23 @@
 
 ISC_LANG_BEGINDECLS
 
+/*% isc_quota_cb - quota callback structure */
+typedef struct isc_quota_cb isc_quota_cb_t;
+typedef void (*isc_quota_cb_func_t)(isc_quota_t *quota, void *data);
+struct isc_quota_cb {
+	isc_quota_cb_func_t cb_func;
+	void *		    data;
+	ISC_LINK(isc_quota_cb_t) link;
+};
+
 /*% isc_quota structure */
 struct isc_quota {
 	atomic_uint_fast32_t max;
 	atomic_uint_fast32_t used;
 	atomic_uint_fast32_t soft;
+	atomic_uint_fast32_t waiting;
+	isc_mutex_t	     cblock;
+	ISC_LIST(isc_quota_cb_t) cbs;
 };
 
 void
@@ -90,41 +102,46 @@ isc_quota_getused(isc_quota_t *quota);
  */
 
 isc_result_t
-isc_quota_reserve(isc_quota_t *quota);
+isc_quota_attach(isc_quota_t *quota, isc_quota_t **p);
 /*%<
- * Attempt to reserve one unit of 'quota'.
+ *
+ * Attempt to reserve one unit of 'quota', and also attaches '*p' to the quota
+ * if successful (ISC_R_SUCCESS or ISC_R_SOFTQUOTA).
  *
  * Returns:
- * \li 	#ISC_R_SUCCESS		Success
+ * \li	#ISC_R_SUCCESS		Success
+ * \li	#ISC_R_SOFTQUOTA	Success soft quota reached
+ * \li	#ISC_R_QUOTA		Quota is full
+ */
+
+isc_result_t
+isc_quota_attach_cb(isc_quota_t *quota, isc_quota_t **p, isc_quota_cb_t *cb);
+/*%<
+ *
+ * Like isc_quota_attach(), but if there's no quota left then cb->cb_func will
+ * be called when we are attached to quota.
+ * Note: It's the callee responsibility to make sure that we don't end up with
+ * extremely huge number of callbacks waiting - making it easy to create a
+ * resource exhaustion attack. For example in case of TCP listening we simply
+ * don't accept new connections - so the number of callbacks waiting in the
+ * queue is limited by listen() backlog.
+ *
+ * Returns:
+ * \li	#ISC_R_SUCCESS		Success
  * \li	#ISC_R_SOFTQUOTA	Success soft quota reached
  * \li	#ISC_R_QUOTA		Quota is full
  */
 
 void
-isc_quota_release(isc_quota_t *quota);
+isc_quota_cb_init(isc_quota_cb_t *cb, isc_quota_cb_func_t cb_func, void *data);
 /*%<
- * Release one unit of quota.
- */
-
-isc_result_t
-isc_quota_attach(isc_quota_t *quota, isc_quota_t **p);
-/*%<
- * Like isc_quota_reserve, and also attaches '*p' to the
- * quota if successful (ISC_R_SUCCESS or ISC_R_SOFTQUOTA).
- */
-
-isc_result_t
-isc_quota_force(isc_quota_t *quota, isc_quota_t **p);
-/*%<
- * Like isc_quota_attach, but will attach '*p' to the quota
- * even if the hard quota has been exceeded.
+ * Initialize isc_quota_cb_t - setup the list, set the callback and data.
  */
 
 void
 isc_quota_detach(isc_quota_t **p);
 /*%<
- * Like isc_quota_release, and also detaches '*p' from the
- * quota.
+ * Release one unit of quota, and also detaches '*p' from the quota.
  */
 
 ISC_LANG_ENDDECLS
diff --git a/lib/isc/quota.c b/lib/isc/quota.c
index 9036dd3f73..137838828f 100644
--- a/lib/isc/quota.c
+++ b/lib/isc/quota.c
@@ -22,14 +22,20 @@ isc_quota_init(isc_quota_t *quota, unsigned int max) {
 	atomic_init(&quota->max, max);
 	atomic_init(&quota->used, 0);
 	atomic_init(&quota->soft, 0);
+	atomic_init(&quota->waiting, 0);
+	ISC_LIST_INIT(quota->cbs);
+	isc_mutex_init(&quota->cblock);
 }
 
 void
 isc_quota_destroy(isc_quota_t *quota) {
 	INSIST(atomic_load(&quota->used) == 0);
+	INSIST(atomic_load(&quota->waiting) == 0);
+	INSIST(ISC_LIST_EMPTY(quota->cbs));
 	atomic_store_release(&quota->max, 0);
 	atomic_store_release(&quota->used, 0);
 	atomic_store_release(&quota->soft, 0);
+	isc_mutex_destroy(&quota->cblock);
 }
 
 void
@@ -57,43 +63,77 @@ isc_quota_getused(isc_quota_t *quota) {
 	return (atomic_load_relaxed(&quota->used));
 }
 
-isc_result_t
-isc_quota_reserve(isc_quota_t *quota) {
+static isc_result_t
+quota_reserve(isc_quota_t *quota) {
 	isc_result_t result;
-	uint32_t max = atomic_load_acquire(&quota->max);
-	uint32_t soft = atomic_load_acquire(&quota->soft);
-	uint32_t used = atomic_fetch_add_relaxed(&quota->used, 1);
-	if (max == 0 || used < max) {
-		if (soft == 0 || used < soft) {
-			result = ISC_R_SUCCESS;
-		} else {
-			result = ISC_R_SOFTQUOTA;
+	uint_fast32_t max = atomic_load_acquire(&quota->max);
+	uint_fast32_t soft = atomic_load_acquire(&quota->soft);
+	uint_fast32_t used = atomic_load_acquire(&quota->used);
+	do {
+		if (max != 0 && used >= max) {
+			return (ISC_R_QUOTA);
 		}
-	} else {
-		INSIST(atomic_fetch_sub_release(&quota->used, 1) > 0);
-		result = ISC_R_QUOTA;
-	}
+		if (soft != 0 && used >= soft) {
+			result = ISC_R_SOFTQUOTA;
+		} else {
+			result = ISC_R_SUCCESS;
+		}
+	} while (!atomic_compare_exchange_weak_acq_rel(&quota->used, &used,
+						       used + 1));
 	return (result);
 }
 
-void
-isc_quota_release(isc_quota_t *quota) {
+/* Must be quota->cbslock locked */
+static void
+enqueue(isc_quota_t *quota, isc_quota_cb_t *cb) {
+	REQUIRE(cb != NULL);
+	ISC_LIST_ENQUEUE(quota->cbs, cb, link);
+	atomic_fetch_add_release(&quota->waiting, 1);
+}
+
+/* Must be quota->cbslock locked */
+static isc_quota_cb_t *
+dequeue(isc_quota_t *quota) {
+	isc_quota_cb_t *cb = ISC_LIST_HEAD(quota->cbs);
+	INSIST(cb != NULL);
+	ISC_LIST_DEQUEUE(quota->cbs, cb, link);
+	atomic_fetch_sub_relaxed(&quota->waiting, 1);
+	return (cb);
+}
+
+static void
+quota_release(isc_quota_t *quota) {
+	/*
+	 * This is opportunistic - we might race with a failing quota_attach_cb
+	 * and not detect that something is waiting, but eventually someone will
+	 * be releasing quota and will detect it, so we don't need to worry -
+	 * and we're saving a lot by not locking cblock every time.
+	 */
+
+	if (atomic_load_acquire(&quota->waiting) > 0) {
+		isc_quota_cb_t *cb = NULL;
+		LOCK(&quota->cblock);
+		if (atomic_load_relaxed(&quota->waiting) > 0) {
+			cb = dequeue(quota);
+		}
+		UNLOCK(&quota->cblock);
+		if (cb != NULL) {
+			cb->cb_func(quota, cb->data);
+			return;
+		}
+	}
+
 	INSIST(atomic_fetch_sub_release(&quota->used, 1) > 0);
 }
 
 static isc_result_t
-doattach(isc_quota_t *quota, isc_quota_t **p, bool force) {
+doattach(isc_quota_t *quota, isc_quota_t **p) {
 	isc_result_t result;
 	REQUIRE(p != NULL && *p == NULL);
 
-	result = isc_quota_reserve(quota);
+	result = quota_reserve(quota);
 	if (result == ISC_R_SUCCESS || result == ISC_R_SOFTQUOTA) {
 		*p = quota;
-	} else if (result == ISC_R_QUOTA && force) {
-		/* attach anyway */
-		atomic_fetch_add_relaxed(&quota->used, 1);
-		*p = quota;
-		result = ISC_R_SUCCESS;
 	}
 
 	return (result);
@@ -101,17 +141,30 @@ doattach(isc_quota_t *quota, isc_quota_t **p, bool force) {
 
 isc_result_t
 isc_quota_attach(isc_quota_t *quota, isc_quota_t **p) {
-	return (doattach(quota, p, false));
+	return (isc_quota_attach_cb(quota, p, NULL));
 }
 
 isc_result_t
-isc_quota_force(isc_quota_t *quota, isc_quota_t **p) {
-	return (doattach(quota, p, true));
+isc_quota_attach_cb(isc_quota_t *quota, isc_quota_t **p, isc_quota_cb_t *cb) {
+	isc_result_t result = doattach(quota, p);
+	if (result == ISC_R_QUOTA && cb != NULL) {
+		LOCK(&quota->cblock);
+		enqueue(quota, cb);
+		UNLOCK(&quota->cblock);
+	}
+	return (result);
+}
+
+void
+isc_quota_cb_init(isc_quota_cb_t *cb, isc_quota_cb_func_t cb_func, void *data) {
+	ISC_LINK_INIT(cb, link);
+	cb->cb_func = cb_func;
+	cb->data = data;
 }
 
 void
 isc_quota_detach(isc_quota_t **p) {
 	INSIST(p != NULL && *p != NULL);
-	isc_quota_release(*p);
+	quota_release(*p);
 	*p = NULL;
 }
diff --git a/lib/isc/tests/Makefile.in b/lib/isc/tests/Makefile.in
index 71a058a84e..6f70b6d301 100644
--- a/lib/isc/tests/Makefile.in
+++ b/lib/isc/tests/Makefile.in
@@ -33,7 +33,7 @@ SRCS =		isctest.c aes_test.c buffer_test.c \
 		counter_test.c crc64_test.c errno_test.c file_test.c hash_test.c \
 		heap_test.c hmac_test.c ht_test.c lex_test.c \
 		mem_test.c md_test.c netaddr_test.c parse_test.c pool_test.c \
-		radix_test.c random_test.c \
+		quota_test.c radix_test.c random_test.c \
 		regex_test.c result_test.c safe_test.c siphash_test.c sockaddr_test.c \
 		socket_test.c socket_test.c symtab_test.c task_test.c \
 		taskpool_test.c time_test.c timer_test.c
@@ -46,7 +46,7 @@ TARGETS =	aes_test@EXEEXT@ buffer_test@EXEEXT@ \
 		ht_test@EXEEXT@ \
 		lex_test@EXEEXT@ mem_test@EXEEXT@ md_test@EXEEXT@ \
 		netaddr_test@EXEEXT@ parse_test@EXEEXT@ pool_test@EXEEXT@ \
-		radix_test@EXEEXT@ \
+		quota_test@EXEEXT@ radix_test@EXEEXT@ \
 		random_test@EXEEXT@ regex_test@EXEEXT@ result_test@EXEEXT@ \
 		safe_test@EXEEXT@ siphash_test@EXEEXT@ sockaddr_test@EXEEXT@ socket_test@EXEEXT@ \
 		socket_test@EXEEXT@ symtab_test@EXEEXT@ task_test@EXEEXT@ \
@@ -134,6 +134,11 @@ pool_test@EXEEXT@: pool_test.@O@ isctest.@O@ ${ISCDEPLIBS}
 		${LDFLAGS} -o $@ pool_test.@O@ isctest.@O@ \
 		${ISCLIBS} ${LIBS}
 
+quota_test@EXEEXT@: quota_test.@O@ isctest.@O@ ${ISCDEPLIBS}
+	${LIBTOOL_MODE_LINK} ${PURIFY} ${CC} ${CFLAGS} \
+		${LDFLAGS} -o $@ quota_test.@O@ isctest.@O@ \
+		${ISCLIBS} ${LIBS}
+
 radix_test@EXEEXT@: radix_test.@O@ isctest.@O@ ${ISCDEPLIBS}
 	${LIBTOOL_MODE_LINK} ${PURIFY} ${CC} ${CFLAGS} \
 		${LDFLAGS} -o $@ radix_test.@O@ isctest.@O@ \
diff --git a/lib/isc/tests/quota_test.c b/lib/isc/tests/quota_test.c
new file mode 100644
index 0000000000..997b253fb2
--- /dev/null
+++ b/lib/isc/tests/quota_test.c
@@ -0,0 +1,343 @@
+/*
+ * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
+ *
+ * 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 http://mozilla.org/MPL/2.0/.
+ *
+ * See the COPYRIGHT file distributed with this work for additional
+ * information regarding copyright ownership.
+ */
+
+#if HAVE_CMOCKA
+
+#include <sched.h> /* IWYU pragma: keep */
+#include <setjmp.h>
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#define UNIT_TESTING
+#include <cmocka.h>
+
+#include <isc/quota.h>
+#include <isc/result.h>
+#include <isc/thread.h>
+#include <isc/util.h>
+
+static void
+isc_quota_get_set_test(void **state) {
+	UNUSED(state);
+	isc_quota_t quota;
+	isc_quota_t *quota2 = NULL;
+	isc_quota_init(&quota, 100);
+
+	assert_int_equal(isc_quota_getmax(&quota), 100);
+	assert_int_equal(isc_quota_getsoft(&quota), 0);
+
+	isc_quota_max(&quota, 50);
+	isc_quota_soft(&quota, 30);
+
+	assert_int_equal(isc_quota_getmax(&quota), 50);
+	assert_int_equal(isc_quota_getsoft(&quota), 30);
+
+	assert_int_equal(isc_quota_getused(&quota), 0);
+	isc_quota_attach(&quota, &quota2);
+	assert_int_equal(isc_quota_getused(&quota), 1);
+	isc_quota_detach(&quota2);
+	assert_int_equal(isc_quota_getused(&quota), 0);
+	isc_quota_destroy(&quota);
+}
+
+#define add_quota(quota, quotasp, exp, attached, exp_used)              \
+	{                                                               \
+		*quotasp = NULL;                                        \
+		isc_result_t result = isc_quota_attach(quota, quotasp); \
+		assert_int_equal(result, exp);                          \
+		if (attached) {                                         \
+			assert_ptr_equal(*quotasp, quota);              \
+		} else {                                                \
+			assert_null(*quotasp);                          \
+		}                                                       \
+		assert_int_equal(isc_quota_getused(quota), exp_used);   \
+	}
+
+static void
+isc_quota_hard_test(void **state) {
+	isc_quota_t quota;
+	isc_quota_t *quotas[110];
+	int i;
+	UNUSED(state);
+
+	isc_quota_init(&quota, 100);
+
+	for (i = 0; i < 100; i++) {
+		add_quota(&quota, &quotas[i], ISC_R_SUCCESS, true, i + 1);
+	}
+
+	add_quota(&quota, &quotas[100], ISC_R_QUOTA, false, 100);
+
+	assert_int_equal(isc_quota_getused(&quota), 100);
+
+	isc_quota_detach(&quotas[0]);
+	assert_null(quotas[0]);
+
+	add_quota(&quota, &quotas[100], ISC_R_SUCCESS, true, 100);
+	add_quota(&quota, &quotas[101], ISC_R_QUOTA, false, 100);
+
+	for (i = 100; i > 0; i--) {
+		isc_quota_detach(&quotas[i]);
+		assert_null(quotas[i]);
+		assert_int_equal(isc_quota_getused(&quota), i - 1);
+	}
+	assert_int_equal(isc_quota_getused(&quota), 0);
+	isc_quota_destroy(&quota);
+}
+
+static void
+isc_quota_soft_test(void **state) {
+	isc_quota_t quota;
+	isc_quota_t *quotas[110];
+	int i;
+	UNUSED(state);
+
+	isc_quota_init(&quota, 100);
+	isc_quota_soft(&quota, 50);
+
+	for (i = 0; i < 50; i++) {
+		add_quota(&quota, &quotas[i], ISC_R_SUCCESS, true, i + 1);
+	}
+	for (i = 50; i < 100; i++) {
+		add_quota(&quota, &quotas[i], ISC_R_SOFTQUOTA, true, i + 1);
+	}
+
+	add_quota(&quota, &quotas[i], ISC_R_QUOTA, false, 100);
+
+	for (i = 99; i >= 0; i--) {
+		isc_quota_detach(&quotas[i]);
+		assert_null(quotas[i]);
+		assert_int_equal(isc_quota_getused(&quota), i);
+	}
+	assert_int_equal(isc_quota_getused(&quota), 0);
+	isc_quota_destroy(&quota);
+}
+
+static atomic_uint_fast32_t cb_calls = ATOMIC_VAR_INIT(0);
+static isc_quota_cb_t cbs[30];
+static isc_quota_t *qp;
+
+static void
+callback(isc_quota_t *quota, void *data) {
+	int val = *(int *)data;
+	/* Callback is not called if we get the quota directly */
+	assert_int_not_equal(val, -1);
+
+	/* We get the proper quota pointer */
+	assert_ptr_equal(quota, qp);
+
+	/* Verify that the callbacks are called in order */
+	int v = atomic_fetch_add_relaxed(&cb_calls, 1);
+	assert_int_equal(v, val);
+
+	/*
+	 * First 5 will be detached by the test function,
+	 * for the last 5 - do a 'chain detach'.
+	 */
+	if (v >= 5) {
+		isc_quota_detach(&quota);
+	}
+}
+
+static void
+isc_quota_callback_test(void **state) {
+	isc_result_t result;
+	isc_quota_t quota;
+	isc_quota_t *quotas[30];
+	qp = &quota;
+	/*
+	 * - 10 calls that end with SUCCESS
+	 * - 10 calls that end with SOFTQUOTA
+	 * - 10 callbacks
+	 */
+	int ints[] = { -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		       -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
+		       0,  1,  2,  3,  4,  5,  6,  7,  8,  9 };
+	int i;
+	UNUSED(state);
+
+	isc_quota_init(&quota, 20);
+	isc_quota_soft(&quota, 10);
+
+	for (i = 0; i < 10; i++) {
+		quotas[i] = NULL;
+		isc_quota_cb_init(&cbs[i], callback, &ints[i]);
+		result = isc_quota_attach_cb(&quota, &quotas[i], &cbs[i]);
+		assert_int_equal(result, ISC_R_SUCCESS);
+		assert_ptr_equal(quotas[i], &quota);
+		assert_int_equal(isc_quota_getused(&quota), i + 1);
+	}
+	for (i = 10; i < 20; i++) {
+		quotas[i] = NULL;
+		isc_quota_cb_init(&cbs[i], callback, &ints[i]);
+		result = isc_quota_attach_cb(&quota, &quotas[i], &cbs[i]);
+		assert_int_equal(result, ISC_R_SOFTQUOTA);
+		assert_ptr_equal(quotas[i], &quota);
+		assert_int_equal(isc_quota_getused(&quota), i + 1);
+	}
+
+	for (i = 20; i < 30; i++) {
+		quotas[i] = NULL;
+		isc_quota_cb_init(&cbs[i], callback, &ints[i]);
+		result = isc_quota_attach_cb(&quota, &quotas[i], &cbs[i]);
+		assert_int_equal(result, ISC_R_QUOTA);
+		assert_ptr_equal(quotas[i], NULL);
+		assert_int_equal(isc_quota_getused(&quota), 20);
+	}
+	assert_int_equal(atomic_load(&cb_calls), 0);
+
+	for (i = 0; i < 5; i++) {
+		isc_quota_detach(&quotas[i]);
+		assert_null(quotas[i]);
+		assert_int_equal(isc_quota_getused(&quota), 20);
+		assert_int_equal(atomic_load(&cb_calls), i + 1);
+	}
+	/* That should cause a chain reaction */
+	isc_quota_detach(&quotas[5]);
+	assert_int_equal(atomic_load(&cb_calls), 10);
+
+	/* Release the quotas that we did not released in the callback */
+	for (i = 0; i < 5; i++) {
+		isc_quota_detach(&quotas[i]);
+	}
+
+	for (i = 6; i < 20; i++) {
+		isc_quota_detach(&quotas[i]);
+		assert_null(quotas[i]);
+		assert_int_equal(isc_quota_getused(&quota), 19 - i);
+	}
+	assert_int_equal(atomic_load(&cb_calls), 10);
+
+	assert_int_equal(isc_quota_getused(&quota), 0);
+	isc_quota_destroy(&quota);
+}
+
+/*
+ * Multithreaded quota callback test:
+ * - quota set to 100
+ * - 10 threads, each trying to get 100 quotas.
+ * - creates a separate thread to release it after 10ms
+ */
+
+typedef struct qthreadinfo {
+	atomic_uint_fast32_t direct;
+	atomic_uint_fast32_t callback;
+	isc_quota_t *quota;
+	isc_quota_cb_t callbacks[100];
+} qthreadinfo_t;
+
+static atomic_uint_fast32_t g_tnum = ATOMIC_VAR_INIT(0);
+/* at most 10 * 100 quota_detach threads */
+isc_thread_t g_threads[10 * 100];
+
+static void *
+quota_detach(void *quotap) {
+	isc_quota_t *quota = (isc_quota_t *)quotap;
+	usleep(10000);
+	isc_quota_detach(&quota);
+	return ((isc_threadresult_t)0);
+}
+
+static void
+quota_callback(isc_quota_t *quota, void *data) {
+	qthreadinfo_t *qti = (qthreadinfo_t *)data;
+	atomic_fetch_add_relaxed(&qti->callback, 1);
+	int tnum = atomic_fetch_add_relaxed(&g_tnum, 1);
+	isc_thread_create(quota_detach, quota, &g_threads[tnum]);
+}
+
+static isc_threadresult_t
+quota_thread(void *qtip) {
+	qthreadinfo_t *qti = (qthreadinfo_t *)qtip;
+	for (int i = 0; i < 100; i++) {
+		isc_quota_cb_init(&qti->callbacks[i], quota_callback, qti);
+		isc_quota_t *quota = NULL;
+		isc_result_t result = isc_quota_attach_cb(qti->quota, &quota,
+							  &qti->callbacks[i]);
+		if (result == ISC_R_SUCCESS) {
+			atomic_fetch_add_relaxed(&qti->direct, 1);
+			int tnum = atomic_fetch_add_relaxed(&g_tnum, 1);
+			isc_thread_create(quota_detach, quota,
+					  &g_threads[tnum]);
+		}
+	}
+	return ((isc_threadresult_t)0);
+}
+
+static void
+isc_quota_callback_mt_test(void **state) {
+	UNUSED(state);
+	isc_quota_t quota;
+	int i;
+
+	isc_quota_init(&quota, 100);
+	static qthreadinfo_t qtis[10];
+	isc_thread_t threads[10];
+	for (i = 0; i < 10; i++) {
+		atomic_init(&qtis[i].direct, 0);
+		atomic_init(&qtis[i].callback, 0);
+		qtis[i].quota = &quota;
+		isc_thread_create(quota_thread, &qtis[i], &threads[i]);
+	}
+	for (i = 0; i < 10; i++) {
+		isc_thread_join(threads[i], NULL);
+	}
+
+	for (i = 0; i < (int)atomic_load(&g_tnum); i++) {
+		isc_thread_join(g_threads[i], NULL);
+	}
+	int direct = 0, callback = 0;
+
+	for (i = 0; i < 10; i++) {
+		direct += atomic_load(&qtis[i].direct);
+		callback += atomic_load(&qtis[i].callback);
+	}
+	/* Total quota gained must be 10 threads * 100 tries */
+	assert_int_equal(direct + callback, 10 * 100);
+	/*
+	 * At least 100 must be direct, the rest is virtually random:
+	 * - in a regular run I'm constantly getting 100:900 ratio
+	 * - under rr - usually around ~120:880
+	 * - under rr -h - 1000:0
+	 */
+	assert_true(direct >= 100);
+
+	isc_quota_destroy(&quota);
+}
+
+int
+main(void) {
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(isc_quota_get_set_test),
+		cmocka_unit_test(isc_quota_hard_test),
+		cmocka_unit_test(isc_quota_soft_test),
+		cmocka_unit_test(isc_quota_callback_test),
+		cmocka_unit_test(isc_quota_callback_mt_test),
+	};
+
+	return (cmocka_run_group_tests(tests, NULL, NULL));
+}
+
+#else /* HAVE_CMOCKA */
+
+#include <stdio.h>
+
+int
+main(void) {
+	printf("1..0 # Skipped: cmocka not available\n");
+	return (0);
+}
+
+#endif /* if HAVE_CMOCKA */
diff --git a/lib/isc/win32/libisc.def.in b/lib/isc/win32/libisc.def.in
index c3dfad5a3e..7cd09bc70f 100644
--- a/lib/isc/win32/libisc.def.in
+++ b/lib/isc/win32/libisc.def.in
@@ -497,16 +497,15 @@ isc_queue_dequeue
 isc_queue_destroy
 isc_queue_new
 isc_quota_attach
+isc_quota_attach_cb
+isc_quota_cb_init
 isc_quota_destroy
 isc_quota_detach
-isc_quota_force
 isc_quota_getmax
 isc_quota_getsoft
 isc_quota_getused
 isc_quota_init
 isc_quota_max
-isc_quota_release
-isc_quota_reserve
 isc_quota_soft
 isc_radix_create
 isc_radix_destroy
diff --git a/util/copyrights b/util/copyrights
index edbe59451e..2087c90769 100644
--- a/util/copyrights
+++ b/util/copyrights
@@ -2314,6 +2314,7 @@
 ./lib/isc/tests/netaddr_test.c			C	2016,2018,2019,2020
 ./lib/isc/tests/parse_test.c			C	2012,2013,2016,2018,2019,2020
 ./lib/isc/tests/pool_test.c			C	2013,2016,2018,2019,2020
+./lib/isc/tests/quota_test.c			C	2020
 ./lib/isc/tests/radix_test.c			C	2014,2016,2018,2019,2020
 ./lib/isc/tests/random_test.c			C	2014,2015,2016,2017,2018,2019,2020
 ./lib/isc/tests/regex_test.c			C	2013,2015,2016,2018,2019,2020