diff --git a/lib/isc/Makefile.am b/lib/isc/Makefile.am
index 839d2723af..fcb8201804 100644
--- a/lib/isc/Makefile.am
+++ b/lib/isc/Makefile.am
@@ -258,10 +258,12 @@ endif HAVE_LIBXML2
 
 if HAVE_LIBNGTCP2
 libisc_la_HEADERS +=			\
-	include/isc/ngtcp2_crypto.h
+	include/isc/ngtcp2_crypto.h	\
+	include/isc/ngtcp2_utils.h
 
 libisc_la_SOURCES +=		\
 	quic/ngtcp2_crypto.c	\
+	quic/ngtcp2_utils.c	\
 	quic/quic_crypto.c	\
 	quic/quic_crypto.h	\
 	quic/quic-int.h	\