diff --git a/src/go/ast/walk.go b/src/go/ast/walk.go
index 73ac38647a..d531f5e714 100644
--- a/src/go/ast/walk.go
+++ b/src/go/ast/walk.go
@@ -379,7 +379,8 @@ func (f inspector) Visit(node Node) Visitor {
 
 // Inspect traverses an AST in depth-first order: It starts by calling
 // f(node); node must not be nil. If f returns true, Inspect invokes f
-// for all the non-nil children of node, recursively.
+// recursively for each of the non-nil children of node, followed by a
+// call of f(nil).
 //
 func Inspect(node Node, f func(Node) bool) {
 	Walk(inspector(f), node)