diff --git a/config/crd/projectcalico.org_ipreservations.yaml b/config/crd/projectcalico.org_ipreservations.yaml
index 19f44a1..46d8d70 100644
--- a/config/crd/projectcalico.org_ipreservations.yaml
+++ b/config/crd/projectcalico.org_ipreservations.yaml
@@ -27,8 +27,8 @@ spec:
             spec:
               properties:
                 reservedCIDRs:
-                  format: cidr
                   items:
+                    format: cidr
                     type: string
                   type: array
                   x-kubernetes-list-type: set
diff --git a/pkg/apis/projectcalico/v3/ipreservation.go b/pkg/apis/projectcalico/v3/ipreservation.go
index 70ada9b..2608df5 100644
--- a/pkg/apis/projectcalico/v3/ipreservation.go
+++ b/pkg/apis/projectcalico/v3/ipreservation.go
@@ -1,4 +1,4 @@
-// Copyright (c) 2017, 2021 Tigera, Inc. All rights reserved.
+// Copyright (c) 2017-2026 Tigera, Inc. All rights reserved.
 
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
@@ -56,7 +56,7 @@ type IPReservation struct {
 type IPReservationSpec struct {
 	// ReservedCIDRs is a list of CIDRs and/or IP addresses that Calico IPAM will exclude from new allocations.
 	// +listType=set
-	// +kubebuilder:validation:Format=cidr
+	// +kubebuilder:validation:items:Format=cidr
 	ReservedCIDRs []string `json:"reservedCIDRs,omitempty" validate:"cidrs,omitempty"`
 }