diff --git a/emulator/bthost.c b/emulator/bthost.c
index f067d39..b051989 100644
--- a/emulator/bthost.c
+++ b/emulator/bthost.c
@@ -137,6 +137,7 @@ struct rfcomm_chan_hook {
 struct iso_hook {
 	bthost_cid_hook_func_t func;
 	void *user_data;
+	bthost_destroy_func_t destroy;
 };
 
 struct btconn {
@@ -306,6 +307,9 @@ static void btconn_free(struct btconn *conn)
 		free(hook);
 	}
 
+	if (conn->iso_hook && conn->iso_hook->destroy)
+		conn->iso_hook->destroy(conn->iso_hook->user_data);
+
 	free(conn->iso_hook);
 	free(conn->recv_data);
 	free(conn);
@@ -676,7 +680,8 @@ void bthost_add_cid_hook(struct bthost *bthost, uint16_t handle, uint16_t cid,
 }
 
 void bthost_add_iso_hook(struct bthost *bthost, uint16_t handle,
-				bthost_cid_hook_func_t func, void *user_data)
+				bthost_iso_hook_func_t func, void *user_data,
+				bthost_destroy_func_t destroy)
 {
 	struct iso_hook *hook;
 	struct btconn *conn;
@@ -693,6 +698,7 @@ void bthost_add_iso_hook(struct bthost *bthost, uint16_t handle,
 
 	hook->func = func;
 	hook->user_data = user_data;
+	hook->destroy = destroy;
 
 	conn->iso_hook = hook;
 }
diff --git a/emulator/bthost.h b/emulator/bthost.h
index 3d7a124..2cfdef7 100644
--- a/emulator/bthost.h
+++ b/emulator/bthost.h
@@ -71,7 +71,8 @@ typedef void (*bthost_iso_hook_func_t)(const void *data, uint16_t len,
 							void *user_data);
 
 void bthost_add_iso_hook(struct bthost *bthost, uint16_t handle,
-				bthost_iso_hook_func_t func, void *user_data);
+				bthost_iso_hook_func_t func, void *user_data,
+				bthost_destroy_func_t destroy);
 
 void bthost_send_cid(struct bthost *bthost, uint16_t handle, uint16_t cid,
 					const void *data, uint16_t len);
diff --git a/tools/iso-tester.c b/tools/iso-tester.c
index 5727f30..8c935b9 100644
--- a/tools/iso-tester.c
+++ b/tools/iso-tester.c
@@ -1137,7 +1137,7 @@ static void iso_send(struct test_data *data, GIOChannel *io)
 	tester_print("Writing %zu bytes of data", isodata->send->iov_len);
 
 	host = hciemu_client_get_host(data->hciemu);
-	bthost_add_iso_hook(host, data->handle, bthost_recv_data, data);
+	bthost_add_iso_hook(host, data->handle, bthost_recv_data, data, NULL);
 
 	ret = writev(sk, isodata->send, 1);
 	if (ret < 0 || isodata->send->iov_len != (size_t) ret) {