diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
index 2fc63edd25..826dd1fb22 100644
--- a/src/cmd/compile/internal/gc/syntax.go
+++ b/src/cmd/compile/internal/gc/syntax.go
@@ -571,7 +571,7 @@ const (
 	ORETURN   // return List
 	OSELECT   // select { List } (List is list of OXCASE or OCASE)
 	OSWITCH   // switch Ninit; Left { List } (List is a list of OXCASE or OCASE)
-	OTYPESW   // List = Left.(type) (appears as .Left of OSWITCH)
+	OTYPESW   // Left = Right.(type) (appears as .Left of OSWITCH)
 
 	// types
 	OTCHAN   // chan int