diff --git a/src/cmd/yacc/doc.go b/src/cmd/yacc/doc.go
index 9874a2a..4a2c2a3 100644
--- a/src/cmd/yacc/doc.go
+++ b/src/cmd/yacc/doc.go
@@ -4,10 +4,13 @@
 
 /*
 
-Yacc is a version of yacc for Go. It is run with the command
-	go tool yacc args...
+Yacc is a version of yacc for Go.
 It is written in Go and generates parsers written in Go.
 
+Usage:
+
+	go tool yacc args...
+
 It is largely transliterated from the Inferno version written in Limbo
 which in turn was largely transliterated from the Plan 9 version
 written in C and documented at