diff --git a/integration/sandbox_clean_remove_test.go b/integration/sandbox_clean_remove_test.go
index ee4843f94..ecfbf1b37 100644
--- a/integration/sandbox_clean_remove_test.go
+++ b/integration/sandbox_clean_remove_test.go
@@ -17,7 +17,6 @@ limitations under the License.
 package integration
 
 import (
-	"encoding/json"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -32,8 +31,6 @@ import (
 	"golang.org/x/net/context"
 	"golang.org/x/sys/unix"
 	runtime "k8s.io/kubernetes/pkg/kubelet/apis/cri/runtime/v1alpha2"
-
-	"github.com/containerd/cri/pkg/server"
 )
 
 func TestSandboxCleanRemove(t *testing.T) {
@@ -77,7 +74,6 @@ func TestSandboxCleanRemove(t *testing.T) {
 }
 
 func TestSandboxRemoveWithoutIPLeakage(t *testing.T) {
-	ctx := context.Background()
 	const hostLocalCheckpointDir = "/var/lib/cni"
 
 	t.Logf("Make sure host-local ipam is in use")
@@ -104,22 +100,13 @@ func TestSandboxRemoveWithoutIPLeakage(t *testing.T) {
 	}()
 
 	t.Logf("Get pod information")
-	client, err := RawRuntimeClient()
+	status, info, err := SandboxInfo(sb)
 	require.NoError(t, err)
-	resp, err := client.PodSandboxStatus(ctx, &runtime.PodSandboxStatusRequest{
-		PodSandboxId: sb,
-		Verbose:      true,
-	})
-	require.NoError(t, err)
-	status := resp.GetStatus()
-	info := resp.GetInfo()
 	ip := status.GetNetwork().GetIp()
 	require.NotEmpty(t, ip)
-	var sbInfo server.SandboxInfo
-	require.NoError(t, json.Unmarshal([]byte(info["info"]), &sbInfo))
-	require.NotNil(t, sbInfo.RuntimeSpec.Linux)
+	require.NotNil(t, info.RuntimeSpec.Linux)
 	var netNS string
-	for _, n := range sbInfo.RuntimeSpec.Linux.Namespaces {
+	for _, n := range info.RuntimeSpec.Linux.Namespaces {
 		if n.Type == runtimespec.NetworkNamespace {
 			netNS = n.Path
 		}
@@ -140,14 +127,23 @@ func TestSandboxRemoveWithoutIPLeakage(t *testing.T) {
 	require.True(t, checkIP(ip))
 
 	t.Logf("Kill sandbox container")
-	require.NoError(t, KillPid(int(sbInfo.Pid)))
+	require.NoError(t, KillPid(int(info.Pid)))
 
 	t.Logf("Unmount network namespace")
-	// The umount will take effect after containerd is stopped.
 	require.NoError(t, unix.Unmount(netNS, unix.MNT_DETACH))
 
-	t.Logf("Restart containerd")
-	RestartContainerd(t)
+	t.Logf("Network namespace should be closed")
+	_, info, err = SandboxInfo(sb)
+	require.NoError(t, err)
+	assert.True(t, info.NetNSClosed)
+
+	t.Logf("Remove network namespace")
+	require.NoError(t, os.RemoveAll(netNS))
+
+	t.Logf("Network namespace should still be closed")
+	_, info, err = SandboxInfo(sb)
+	require.NoError(t, err)
+	assert.True(t, info.NetNSClosed)
 
 	t.Logf("Sandbox state should be NOTREADY")
 	assert.NoError(t, Eventually(func() (bool, error) {
@@ -158,14 +154,10 @@ func TestSandboxRemoveWithoutIPLeakage(t *testing.T) {
 		return status.GetState() == runtime.PodSandboxState_SANDBOX_NOTREADY, nil
 	}, time.Second, 30*time.Second), "sandbox state should become NOTREADY")
 
-	t.Logf("Network namespace should have been removed")
-	_, err = os.Stat(netNS)
-	assert.True(t, os.IsNotExist(err))
-
 	t.Logf("Should still be able to find the pod ip in host-local checkpoint")
 	assert.True(t, checkIP(ip))
 
-	t.Logf("Should be able to remove the sandbox after properly stopped")
+	t.Logf("Should be able to stop and remove the sandbox")
 	assert.NoError(t, runtimeService.StopPodSandbox(sb))
 	assert.NoError(t, runtimeService.RemovePodSandbox(sb))
 
diff --git a/integration/test_utils.go b/integration/test_utils.go
index a2e598f77..12507dab6 100644
--- a/integration/test_utils.go
+++ b/integration/test_utils.go
@@ -42,6 +42,7 @@ import (
 	"github.com/containerd/cri/pkg/client"
 	criconfig "github.com/containerd/cri/pkg/config"
 	"github.com/containerd/cri/pkg/constants"
+	"github.com/containerd/cri/pkg/server"
 	"github.com/containerd/cri/pkg/util"
 )
 
@@ -352,6 +353,27 @@ func CRIConfig() (*criconfig.Config, error) {
 	return config, nil
 }
 
+// SandboxInfo gets sandbox info.
+func SandboxInfo(id string) (*runtime.PodSandboxStatus, *server.SandboxInfo, error) {
+	client, err := RawRuntimeClient()
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "failed to get raw runtime client")
+	}
+	resp, err := client.PodSandboxStatus(context.Background(), &runtime.PodSandboxStatusRequest{
+		PodSandboxId: id,
+		Verbose:      true,
+	})
+	if err != nil {
+		return nil, nil, errors.Wrap(err, "failed to get sandbox status")
+	}
+	status := resp.GetStatus()
+	var info server.SandboxInfo
+	if err := json.Unmarshal([]byte(resp.GetInfo()["info"]), &info); err != nil {
+		return nil, nil, errors.Wrap(err, "failed to unmarshal sandbox info")
+	}
+	return status, &info, nil
+}
+
 func RestartContainerd(t *testing.T) {
 	require.NoError(t, KillProcess("containerd"))