diff --git a/src/quic_frame.c b/src/quic_frame.c
index c06816f..0cbae59 100644
--- a/src/quic_frame.c
+++ b/src/quic_frame.c
@@ -1016,7 +1016,7 @@
 		return 0;
 	}
 
-	pkt->flags |= builder[frm->type].flags;
+	pkt->flags |= builder->flags;
 
 	return 1;
 }