diff --git a/test/e2e/backup_test.go b/test/e2e/backup_test.go
index 21f7ff2e..b1e3b0af 100644
--- a/test/e2e/backup_test.go
+++ b/test/e2e/backup_test.go
@@ -9,9 +9,6 @@ import (
 	"github.com/cybozu-go/mantle/test/util"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
-	"k8s.io/apimachinery/pkg/api/meta"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
-	"sigs.k8s.io/yaml"
 )
 
 const (
@@ -154,6 +151,18 @@ func (test *backupTest) testCase1() {
 
 			return checkSnapshotExist(cephCluster1Namespace, test.poolName, imageName, test.mantleBackupName3)
 		}).Should(Succeed())
+
+		By("Checking that the status.conditions of the MantleBackup resource becomes \"ReadyToUse\"")
+		Eventually(func() error {
+			ready, err := isMantleBackupReady(test.tenantNamespace, test.mantleBackupName3)
+			if err != nil {
+				return err
+			}
+			if !ready {
+				return fmt.Errorf("not ready")
+			}
+			return nil
+		}).Should(Succeed())
 	})
 
 	It("should not delete MantleBackup resource when delete backup target PVC", func() {
@@ -173,14 +182,10 @@ func (test *backupTest) testCase1() {
 			return fmt.Errorf("PVC %s still exists. stdout: %s", test.pvcName2, stdout)
 		}).Should(Succeed())
 
-		By("Checking that the status.conditions of the MantleBackup resource remain \"Bound\"")
-		stdout, _, err := kubectl("-n", test.tenantNamespace, "get", "mantlebackup", test.mantleBackupName3, "-o", "json")
-		Expect(err).NotTo(HaveOccurred())
-		var backup mantlev1.MantleBackup
-		err = yaml.Unmarshal(stdout, &backup)
+		By("Checking that the status.conditions of the MantleBackup resource remain \"ReadyToUse\"")
+		ready, err := isMantleBackupReady(test.tenantNamespace, test.mantleBackupName3)
 		Expect(err).NotTo(HaveOccurred())
-		Expect(meta.FindStatusCondition(backup.Status.Conditions, mantlev1.BackupConditionReadyToUse).Status).
-			To(Equal(metav1.ConditionTrue))
+		Expect(ready).To(Equal(true))
 	})
 
 	It("should delete MantleBackup resource", func() {
diff --git a/test/e2e/util.go b/test/e2e/util.go
index c10d5de5..6a451d92 100644
--- a/test/e2e/util.go
+++ b/test/e2e/util.go
@@ -13,6 +13,7 @@ import (
 	mantlev1 "github.com/cybozu-go/mantle/api/v1"
 	"github.com/cybozu-go/mantle/internal/controller"
 	testutil "github.com/cybozu-go/mantle/test/util"
+	"gopkg.in/yaml.v2"
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/meta"
@@ -401,6 +402,20 @@ func getRBDInfo(clusterNS, pool, image string) (*rbdInfo, error) {
 	return &info, nil
 }
 
+func isMantleBackupReady(namespace, name string) (bool, error) {
+	stdout, _, err := kubectl("-n", namespace, "get", "mantlebackup", name, "-o", "json")
+	if err != nil {
+		return false, err
+	}
+	var backup mantlev1.MantleBackup
+	err = yaml.Unmarshal(stdout, &backup)
+	if err != nil {
+		return false, err
+	}
+	cond := meta.FindStatusCondition(backup.Status.Conditions, mantlev1.BackupConditionReadyToUse).Status
+	return cond == metav1.ConditionTrue, nil
+}
+
 func isMantleRestoreReady(namespace, name string) bool {
 	stdout, stderr, err := kubectl("get", "mantlerestore", "-n", namespace, name, "-o", "json")
 	if err != nil {