diff --git a/ex/check-soa/check-soa.go b/ex/check-soa/check-soa.go
index 6dcda2fc..9c29082c 100644
--- a/ex/check-soa/check-soa.go
+++ b/ex/check-soa/check-soa.go
@@ -1,3 +1,4 @@
+// Go equivalent of the "DNS & BIND" book check-soa program.
 package main
 
 import (