diff --git a/external/ngtcp2 b/external/ngtcp2
index bd19d73eb..15ba6021c 160000
--- a/external/ngtcp2
+++ b/external/ngtcp2
@@ -1 +1 @@
-Subproject commit bd19d73eb949d8cdd665342ffe29e772f3103506
+Subproject commit 15ba6021ca352e2e60f9b43f4b96d2e97a42f60b