diff --git a/emulator/btdev.c b/emulator/btdev.c
index 086885d..ec52c52 100644
--- a/emulator/btdev.c
+++ b/emulator/btdev.c
@@ -4873,14 +4873,15 @@ static int cmd_set_ext_adv_params(struct btdev *dev, const void *data,
 
 	ext_adv->type = le16_to_cpu(cmd->evt_properties);
 
-	/* In case of direct advertising (type == 0x01) the advertising
-	 * intervals shall be ignored and high duty cycle shall be used.
+	/* In case of high duty cycle directed connectable advertising
+	 * intervals shall be ignored and high duty cycle shall be used
+	 * (advertising interval <= 3.75 ms).
 	 */
-	if (ext_adv->type == 0x01)
-		ext_adv->interval = 10;
+	if ((ext_adv->type & 0x0D) == 0x0D /* 0b1101 */)
+		ext_adv->interval = 3;
 	else {
 		unsigned int min_interval = get_le24(cmd->min_interval);
-		if (min_interval < 0x0020 || min_interval > 0x4000) {
+		if (min_interval < 0x0020 || min_interval > 0xFFFFFF) {
 			rsp.status = BT_HCI_ERR_UNSUPPORTED_FEATURE;
 			cmd_complete(dev, BT_HCI_CMD_LE_SET_EXT_ADV_PARAMS,
 						&rsp, sizeof(rsp));
diff --git a/emulator/bthost.c b/emulator/bthost.c
index 9516050..a76b02e 100644
--- a/emulator/bthost.c
+++ b/emulator/bthost.c
@@ -3249,11 +3249,14 @@ void bthost_set_scan_enable(struct bthost *bthost, uint8_t enable)
 
 void bthost_set_ext_adv_params(struct bthost *bthost)
 {
+	const uint8_t interval_20ms[] = { 0x20, 0x00, 0x00 };
 	struct bt_hci_cmd_le_set_ext_adv_params cp;
 
 	memset(&cp, 0, sizeof(cp));
 	cp.handle = 0x01;
 	cp.evt_properties = cpu_to_le16(0x0013);
+	memcpy(cp.min_interval, interval_20ms, sizeof(cp.min_interval));
+	memcpy(cp.max_interval, interval_20ms, sizeof(cp.max_interval));
 	send_command(bthost, BT_HCI_CMD_LE_SET_EXT_ADV_PARAMS,
 							&cp, sizeof(cp));
 }