diff --git a/staging/src/k8s.io/apiserver/pkg/cel/library/cost.go b/staging/src/k8s.io/apiserver/pkg/cel/library/cost.go
index e3bde017bea..06005b4e806 100644
--- a/staging/src/k8s.io/apiserver/pkg/cel/library/cost.go
+++ b/staging/src/k8s.io/apiserver/pkg/cel/library/cost.go
@@ -21,10 +21,10 @@ import (
 
 	"github.com/google/cel-go/checker"
 	"github.com/google/cel-go/common"
+	"github.com/google/cel-go/common/ast"
 	"github.com/google/cel-go/common/types"
 	"github.com/google/cel-go/common/types/ref"
 	"github.com/google/cel-go/common/types/traits"
-	exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
 )
 
 // CostEstimator implements CEL's interpretable.ActualCostEstimator and checker.CostEstimator.
@@ -255,8 +255,10 @@ func (l *CostEstimator) EstimateCallCost(function, overloadId string, target *ch
 			// Worst case size is where is that a separator of "" is used, and each char is returned as a list element.
 			max := sz.Max
 			if len(args) > 1 {
-				if c := args[1].Expr().GetConstExpr(); c != nil {
-					max = uint64(c.GetInt64Value())
+				if v := args[1].Expr().AsLiteral(); v != nil {
+					if i, ok := v.Value().(int64); ok {
+						max = uint64(i)
+					}
 				}
 			}
 			// Cost is the traversal plus the construction of the result.
@@ -425,7 +427,7 @@ func (l *CostEstimator) EstimateSize(element checker.AstNode) *checker.SizeEstim
 type itemsNode struct {
 	path []string
 	t    *types.Type
-	expr *exprpb.Expr
+	expr ast.Expr
 }
 
 func (i *itemsNode) Path() []string {
@@ -436,7 +438,7 @@ func (i *itemsNode) Type() *types.Type {
 	return i.t
 }
 
-func (i *itemsNode) Expr() *exprpb.Expr {
+func (i *itemsNode) Expr() ast.Expr {
 	return i.expr
 }
 
@@ -444,6 +446,8 @@ func (i *itemsNode) ComputedSize() *checker.SizeEstimate {
 	return nil
 }
 
+var _ checker.AstNode = (*itemsNode)(nil)
+
 // traversalCost computes the cost of traversing a ref.Val as a data tree.
 func traversalCost(v ref.Val) uint64 {
 	// TODO: This could potentially be optimized by sampling maps and lists instead of traversing.
diff --git a/staging/src/k8s.io/apiserver/pkg/cel/library/cost_test.go b/staging/src/k8s.io/apiserver/pkg/cel/library/cost_test.go
index 03ba0c504b5..7e1e878eecb 100644
--- a/staging/src/k8s.io/apiserver/pkg/cel/library/cost_test.go
+++ b/staging/src/k8s.io/apiserver/pkg/cel/library/cost_test.go
@@ -23,6 +23,7 @@ import (
 
 	"github.com/google/cel-go/cel"
 	"github.com/google/cel-go/checker"
+	"github.com/google/cel-go/common/ast"
 	"github.com/google/cel-go/common/types"
 	"github.com/google/cel-go/ext"
 	exprpb "google.golang.org/genproto/googleapis/api/expr/v1alpha1"
@@ -1147,6 +1148,8 @@ type testSizeNode struct {
 	size checker.SizeEstimate
 }
 
+var _ checker.AstNode = (*testSizeNode)(nil)
+
 func (t testSizeNode) Path() []string {
 	return nil // not needed
 }
@@ -1155,7 +1158,7 @@ func (t testSizeNode) Type() *types.Type {
 	return nil // not needed
 }
 
-func (t testSizeNode) Expr() *exprpb.Expr {
+func (t testSizeNode) Expr() ast.Expr {
 	return nil // not needed
 }