diff --git a/integration_tests/pd_api_test.go b/integration_tests/pd_api_test.go
index 1d45b4917..a990c9cad 100644
--- a/integration_tests/pd_api_test.go
+++ b/integration_tests/pd_api_test.go
@@ -52,6 +52,7 @@ func (s *apiTestSuite) SetupTest() {
 	pdClient, err := pd.NewClient(addrs, pd.SecurityOption{})
 	s.Require().NoError(err)
 	rpcClient := tikv.NewRPCClient()
+	s.Require().NoError(failpoint.Enable("tikvclient/mockFastSafeTSUpdater", `return()`))
 	// Set PD HTTP client.
 	store, err := tikv.NewTestTiKVStore(rpcClient, pdClient, nil, nil, 0, tikv.WithPDHTTPClient(nil, addrs))
 	s.store = store
@@ -101,10 +102,8 @@ func (c *storeSafeTsMockClient) CloseAddr(addr string) error {
 func (s *apiTestSuite) TestGetStoresMinResolvedTS() {
 	util.EnableFailpoints()
 	require := s.Require()
-	require.NoError(failpoint.Enable("tikvclient/mockFastSafeTSUpdater", `return()`))
-	defer func() {
-		require.NoError(failpoint.Disable("tikvclient/mockFastSafeTSUpdater"))
-	}()
+	mockClient := newStoreSafeTsMockClient(s.store.GetTiKVClient())
+	s.store.SetTiKVClient(&mockClient)
 
 	// Set DC label for store 1.
 	// Mock Cluster-level min resolved ts failed.
@@ -124,8 +123,6 @@ func (s *apiTestSuite) TestGetStoresMinResolvedTS() {
 	s.store.GetRegionCache().SetRegionCacheStore(storeID, s.storeAddr(storeID), s.storeAddr(storeID), tikvrpc.TiKV, 1, labels)
 	// Try to get the minimum resolved timestamp of the stores from PD.
 	require.NoError(failpoint.Enable("tikvclient/InjectMinResolvedTS", `return(100)`))
-	mockClient := newStoreSafeTsMockClient(s.store.GetTiKVClient())
-	s.store.SetTiKVClient(&mockClient)
 	var retryCount int
 	for s.store.GetMinSafeTS(dcLabel) != 100 {
 		time.Sleep(100 * time.Millisecond)
@@ -136,20 +133,16 @@ func (s *apiTestSuite) TestGetStoresMinResolvedTS() {
 	}
 	require.Equal(int32(0), atomic.LoadInt32(&mockClient.requestCount))
 	require.Equal(uint64(100), s.store.GetMinSafeTS(dcLabel))
-	require.Nil(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
+	require.NoError(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
 }
 
 func (s *apiTestSuite) TestDCLabelClusterMinResolvedTS() {
 	util.EnableFailpoints()
-	// Try to get the minimum resolved timestamp of the cluster from PD.
 	require := s.Require()
-	require.NoError(failpoint.Enable("tikvclient/mockFastSafeTSUpdater", `return()`))
-	defer func() {
-		require.NoError(failpoint.Disable("tikvclient/mockFastSafeTSUpdater"))
-	}()
-	require.NoError(failpoint.Enable("tikvclient/InjectMinResolvedTS", `return(100)`))
 	mockClient := newStoreSafeTsMockClient(s.store.GetTiKVClient())
 	s.store.SetTiKVClient(&mockClient)
+	// Try to get the minimum resolved timestamp of the cluster from PD.
+	require.NoError(failpoint.Enable("tikvclient/InjectMinResolvedTS", `return(100)`))
 	var retryCount int
 	for s.store.GetMinSafeTS(oracle.GlobalTxnScope) != 100 {
 		time.Sleep(100 * time.Millisecond)
@@ -165,9 +158,6 @@ func (s *apiTestSuite) TestDCLabelClusterMinResolvedTS() {
 	// Set DC label for store 1.
 	// Mock PD server not support get min resolved ts by stores.
 	require.NoError(failpoint.Enable("tikvclient/InjectMinResolvedTS", `return(0)`))
-	defer func() {
-		require.NoError(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
-	}()
 	dcLabel := "testDC"
 	restore := config.UpdateGlobal(func(conf *config.Config) {
 		conf.TxnScope = dcLabel
@@ -182,7 +172,6 @@ func (s *apiTestSuite) TestDCLabelClusterMinResolvedTS() {
 	}
 	storeID := uint64(1)
 	s.store.GetRegionCache().SetRegionCacheStore(storeID, s.storeAddr(storeID), s.storeAddr(storeID), tikvrpc.TiKV, 1, labels)
-
 	// Try to get the minimum resolved timestamp of the store from TiKV.
 	retryCount = 0
 	for s.store.GetMinSafeTS(dcLabel) != 150 {
@@ -195,18 +184,15 @@ func (s *apiTestSuite) TestDCLabelClusterMinResolvedTS() {
 
 	require.GreaterOrEqual(atomic.LoadInt32(&mockClient.requestCount), int32(1))
 	require.Equal(uint64(150), s.store.GetMinSafeTS(dcLabel))
+	require.NoError(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
 }
 
 func (s *apiTestSuite) TestInitClusterMinResolvedTSZero() {
 	util.EnableFailpoints()
 	require := s.Require()
-	require.NoError(failpoint.Enable("tikvclient/mockFastSafeTSUpdater", `return()`))
-	defer func() {
-		require.NoError(failpoint.Disable("tikvclient/mockFastSafeTSUpdater"))
-	}()
-
 	mockClient := newStoreSafeTsMockClient(s.store.GetTiKVClient())
 	s.store.SetTiKVClient(&mockClient)
+
 	// Make sure the store's min resolved ts is not initialized.
 	mockClient.SetKVSafeTS(0)
 	// Try to get the minimum resolved timestamp of the cluster from TiKV.
@@ -219,6 +205,9 @@ func (s *apiTestSuite) TestInitClusterMinResolvedTSZero() {
 		}
 		retryCount++
 	}
+	// Make sure the store's min resolved ts is not initialized.
+	require.Equal(uint64(math.MaxUint64), s.store.GetMinSafeTS(oracle.GlobalTxnScope))
+	require.NoError(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
 
 	// Try to get the minimum resolved timestamp of the cluster from PD.
 	require.NoError(failpoint.Enable("tikvclient/InjectMinResolvedTS", `return(100)`))
@@ -230,6 +219,7 @@ func (s *apiTestSuite) TestInitClusterMinResolvedTSZero() {
 		}
 		retryCount++
 	}
+	// Make sure the store's min resolved ts is not regarded as MaxUint64.
 	require.Equal(uint64(100), s.store.GetMinSafeTS(oracle.GlobalTxnScope))
 	require.NoError(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
 
@@ -244,6 +234,7 @@ func (s *apiTestSuite) TestInitClusterMinResolvedTSZero() {
 		}
 		retryCount++
 	}
+	// Make sure the minSafeTS can advance.
 	require.Equal(uint64(150), s.store.GetMinSafeTS(oracle.GlobalTxnScope))
 	require.NoError(failpoint.Disable("tikvclient/InjectMinResolvedTS"))
 }
@@ -252,4 +243,5 @@ func (s *apiTestSuite) TearDownTest() {
 	if s.store != nil {
 		s.Require().Nil(s.store.Close())
 	}
+	s.Require().NoError(failpoint.Disable("tikvclient/mockFastSafeTSUpdater"))
 }