diff --git a/doc/rfc/index b/doc/rfc/index
index dbbdd20761..d94158d18a 100644
--- a/doc/rfc/index
+++ b/doc/rfc/index
@@ -64,5 +64,6 @@
 3008:   Domain Name System Security (DNSSEC) Signing Authority
 3090:	DNS Security Extension Clarification on Zone Status
 3110:	RSA/SHA-1 SIGs and RSA KEYs in the Domain Name System (DNS)
+3123:	A DNS RR Type for Lists of Address Prefixes (APL RR)
 3225:	Indicating Resolver Support of DNSSEC
 3226:	DNSSEC and IPv6 A6 aware server/resolver message size requirements