diff --git a/cmd/golangorg/codewalk.go b/cmd/golangorg/codewalk.go
index e3bf5cd..91c8cdc 100644
--- a/cmd/golangorg/codewalk.go
+++ b/cmd/golangorg/codewalk.go
@@ -287,7 +287,7 @@
 
 // addrToByte evaluates the given address starting at offset start in data.
 // It returns the lo and hi byte offset of the matched region within data.
-// See http://plan9.bell-labs.com/sys/doc/sam/sam.html Table II
+// See https://9p.io/sys/doc/sam/sam.html Table II
 // for details on the syntax.
 func addrToByteRange(addr string, start int, data []byte) (lo, hi int, err error) {
 	var (