diff --git a/channels/chan_dahdi.c b/channels/chan_dahdi.c
index ef2f19e..62f3fbe 100644
--- a/channels/chan_dahdi.c
+++ b/channels/chan_dahdi.c
@@ -2680,6 +2680,7 @@ static void my_handle_dchan_exception(struct sig_pri_span *pri, int index)
 		pri_event_noalarm(pri, index, 0);
 		break;
 	case DAHDI_EVENT_REMOVED:
+		ast_mutex_unlock(&pri->lock);
 		pri_destroy_span(pri);
 		break;
 	default:
@@ -14161,6 +14162,7 @@ static void pri_destroy_span(struct sig_pri_span *pri)
 		dahdi_destroy_channel_range(channel, channel);
 	}
 
+	ast_mutex_lock(&pri->lock);
 	cancel_code = pthread_cancel(master);
 	pthread_kill(master, SIGURG);
 	ast_debug(4,