diff --git a/src/go/ast/walk.go b/src/go/ast/walk.go
index 9224264e291..ac1395fafdb 100644
--- a/src/go/ast/walk.go
+++ b/src/go/ast/walk.go
@@ -112,7 +112,11 @@ func Walk(v Visitor, node Node) {
 
 	case *IndexExpr:
 		Walk(v, n.X)
-		Walk(v, n.Index)
+		// n.Index may be nil for invalid type instantiation expressions, e.g.
+		// var x T[].
+		if n.Index != nil {
+			Walk(v, n.Index)
+		}
 
 	case *SliceExpr:
 		Walk(v, n.X)
diff --git a/src/go/ast/walk_typeparams.go b/src/go/ast/walk_typeparams.go
index 77267a5b8c7..b6621335b8e 100644
--- a/src/go/ast/walk_typeparams.go
+++ b/src/go/ast/walk_typeparams.go
@@ -7,6 +7,10 @@
 
 package ast
 
+import (
+	"fmt"
+)
+
 func walkFuncTypeParams(v Visitor, n *FuncType) {
 	if n.TParams != nil {
 		Walk(v, n.TParams)
@@ -20,9 +24,11 @@ func walkTypeSpecParams(v Visitor, n *TypeSpec) {
 }
 
 func walkOtherNodes(v Visitor, n Node) {
-	if e, ok := n.(*ast.ListExpr); ok {
+	if e, ok := n.(*ListExpr); ok {
 		if e != nil {
-			Walk(v, e)
+			for _, elem := range e.ElemList {
+				Walk(v, elem)
+			}
 		}
 	} else {
 		panic(fmt.Sprintf("ast.Walk: unexpected node type %T", n))