diff --git a/ddl/column_type_change_test.go b/ddl/column_type_change_test.go
index 2fed091c5be3f..467d0f7eab34b 100644
--- a/ddl/column_type_change_test.go
+++ b/ddl/column_type_change_test.go
@@ -619,7 +619,7 @@ func TestColumnTypeChangeFromStringToOthers(t *testing.T) {
 	tk.MustExec("alter table t modify txt json")
 	tk.MustExec("alter table t modify e json")
 	tk.MustExec("alter table t modify s json")
-	tk.MustQuery("select * from t").Check(testkit.Rows("{\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} \"{\\\"k1\\\": \\\"value\\\"}\" \"{\\\"k1\\\": \\\"value\\\"}\""))
+	tk.MustQuery("select * from t").Check(testkit.Rows("{\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"} {\"k1\": \"value\"}"))
 
 	reset(tk)
 	tk.MustExec("insert into t values ('123x', 'x123', 'abc', 'datetime', 'timestamp', 'date', '123', '123')")
@@ -651,7 +651,10 @@ func TestColumnTypeChangeFromStringToOthers(t *testing.T) {
 	reset(tk)
 	tk.MustExec("alter table t modify c char(15)")
 	tk.MustExec("insert into t(c) values ('{\"k1\": \"value\"')")
+	tk.MustExec("insert into t(e, s) values ('str', 'str')")
 	tk.MustGetErrCode("alter table t modify c json", errno.ErrInvalidJSONText)
+	tk.MustGetErrCode("alter table t modify e json", errno.ErrInvalidJSONText)
+	tk.MustGetErrCode("alter table t modify s json", errno.ErrInvalidJSONText)
 
 	// MySQL will get "ERROR 1366 (HY000): Incorrect DECIMAL value: '0' for column '' at row -1" error.
 	tk.MustExec("insert into t(vc) values ('abc')")
diff --git a/types/datum.go b/types/datum.go
index 41de0fa821a7d..7c08bea7a6666 100644
--- a/types/datum.go
+++ b/types/datum.go
@@ -1673,6 +1673,14 @@ func (d *Datum) convertToMysqlJSON(_ *stmtctx.StatementContext, _ *FieldType) (r
 		if j, err = json.ParseBinaryFromString(d.GetString()); err == nil {
 			ret.SetMysqlJSON(j)
 		}
+	case KindMysqlSet, KindMysqlEnum:
+		var j json.BinaryJSON
+		var s string
+		if s, err = d.ToString(); err == nil {
+			if j, err = json.ParseBinaryFromString(s); err == nil {
+				ret.SetMysqlJSON(j)
+			}
+		}
 	case KindInt64:
 		i64 := d.GetInt64()
 		ret.SetMysqlJSON(json.CreateBinary(i64))