diff --git a/emulator/btdev.c b/emulator/btdev.c
index 7293e2f..3747eaa 100644
--- a/emulator/btdev.c
+++ b/emulator/btdev.c
@@ -6538,7 +6538,33 @@ static int cmd_create_big_test(struct btdev *dev, const void *data, uint8_t len)
 
 static int cmd_term_big(struct btdev *dev, const void *data, uint8_t len)
 {
-	cmd_status(dev, BT_HCI_ERR_SUCCESS, BT_HCI_CMD_LE_TERM_BIG);
+	const struct bt_hci_cmd_le_term_big *cmd = data;
+	struct le_big *big;
+	uint8_t status = BT_HCI_ERR_SUCCESS;
+
+	/* Check that PA advertising is enabled othewise it is not possible to
+	 * have a BIG.
+	 */
+	if (!dev->le_pa_enable) {
+		status = BT_HCI_ERR_UNKNOWN_ADVERTISING_ID;
+		goto done;
+	}
+
+	/* If the BIG_Handle does not identify a BIG, the Controller shall
+	 * return the error code Unknown Advertising Identifier (0x42).
+	 */
+	big = queue_find(dev->le_big, match_big_handle,
+			UINT_TO_PTR(cmd->handle));
+	if (!big) {
+		status = BT_HCI_ERR_UNKNOWN_ADVERTISING_ID;
+		goto done;
+	}
+
+done:
+	cmd_status(dev, status, BT_HCI_CMD_LE_TERM_BIG);
+
+	if (status)
+		return -EALREADY;
 
 	return 0;
 }
@@ -6548,6 +6574,9 @@ static int cmd_term_big_complete(struct btdev *dev, const void *data,
 {
 	const struct bt_hci_cmd_le_term_big *cmd = data;
 	struct bt_hci_evt_le_big_terminate rsp;
+	struct le_big *big;
+	struct btdev_conn *conn;
+	struct btdev *remote = NULL;
 
 	memset(&rsp, 0, sizeof(rsp));
 	rsp.reason = cmd->reason;
@@ -6555,6 +6584,40 @@ static int cmd_term_big_complete(struct btdev *dev, const void *data,
 
 	le_meta_event(dev, BT_HCI_EVT_LE_BIG_TERMINATE, &rsp, sizeof(rsp));
 
+	big = queue_find(dev->le_big, match_big_handle,
+			UINT_TO_PTR(cmd->handle));
+
+	if (!big)
+		return 0;
+
+	/* Cleanup existing connections */
+	while ((conn = queue_pop_head(big->bis))) {
+		if (!conn->link) {
+			conn_remove(conn);
+			continue;
+		}
+
+		/* Send BIG Sync Lost event once per remote device */
+		if (conn->link->dev != remote) {
+			struct bt_hci_evt_le_big_sync_lost evt;
+
+			memset(&evt, 0, sizeof(evt));
+			evt.big_handle = cmd->handle;
+			evt.reason = cmd->reason;
+
+			remote = conn->link->dev;
+			le_meta_event(remote, BT_HCI_EVT_LE_BIG_SYNC_LOST,
+				      &evt, sizeof(evt));
+		}
+
+		/* Unlink conn from remote BIS */
+		conn_unlink(conn, conn->link);
+		conn_remove(conn);
+	}
+
+	queue_remove(dev->le_big, big);
+	le_big_free(big);
+
 	return 0;
 }
 
@@ -7587,6 +7650,8 @@ static const struct btdev_cmd *run_cmd(struct btdev *btdev,
 	case -ENOENT:
 		status = BT_HCI_ERR_UNKNOWN_CONN_ID;
 		break;
+	case -EALREADY:
+		return NULL;
 	default:
 		status = BT_HCI_ERR_UNSPECIFIED_ERROR;
 		break;