diff --git a/ddl/column_test.go b/ddl/column_test.go
index 10b883a76935a..289f026bf1d0a 100644
--- a/ddl/column_test.go
+++ b/ddl/column_test.go
@@ -1159,6 +1159,8 @@ func (s *testColumnSuite) TestModifyColumn(c *C) {
 		WithLease(testLease),
 	)
 	ctx := testNewContext(d)
+	ctx.GetSessionVars().EnableChangeColumnType = false
+
 	defer func() {
 		err := d.Stop()
 		c.Assert(err, IsNil)
diff --git a/ddl/column_type_change_test.go b/ddl/column_type_change_test.go
index 8e3f7d6d30e8a..5764875a75e7f 100644
--- a/ddl/column_type_change_test.go
+++ b/ddl/column_type_change_test.go
@@ -1651,6 +1651,7 @@ func (s *testColumnTypeChangeSuite) TestRowFormat(c *C) {
 func (s *testColumnTypeChangeSuite) TestColumnTypeChangeFlenErrorMsg(c *C) {
 	tk := testkit.NewTestKit(c, s.store)
 	tk.MustExec("use test")
+	tk.Se.GetSessionVars().EnableChangeColumnType = false
 
 	tk.MustExec("drop table if exists t")
 	tk.MustExec("create table t(a int4)")
diff --git a/ddl/db_change_test.go b/ddl/db_change_test.go
index 041f35c7734a8..befcd8d31c8c3 100644
--- a/ddl/db_change_test.go
+++ b/ddl/db_change_test.go
@@ -82,6 +82,11 @@ func (s *testStateChangeSuiteBase) SetUpSuite(c *C) {
 	c.Assert(err, IsNil)
 	_, err = s.se.Execute(context.Background(), "use test_db_state")
 	c.Assert(err, IsNil)
+	// Set the variable to default 0 as it was before in case of modifying the test.
+	_, err = s.se.Execute(context.Background(), "set @@global.tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
+	_, err = s.se.Execute(context.Background(), "set @@tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
 	s.p = parser.New()
 }
 
diff --git a/ddl/db_integration_test.go b/ddl/db_integration_test.go
index c65fb27de399e..e37585ce384e8 100644
--- a/ddl/db_integration_test.go
+++ b/ddl/db_integration_test.go
@@ -88,6 +88,10 @@ func setupIntegrationSuite(s *testIntegrationSuite, c *C) {
 	s.ctx = se.(sessionctx.Context)
 	_, err = se.Execute(context.Background(), "create database test_db")
 	c.Assert(err, IsNil)
+	_, err = se.Execute(context.Background(), "set @@global.tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
+	_, err = se.Execute(context.Background(), "set @@tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
 }
 
 func tearDownIntegrationSuiteTest(s *testIntegrationSuite, c *C) {
diff --git a/ddl/db_test.go b/ddl/db_test.go
index 2a114b49d205f..e67b0a9c1795f 100644
--- a/ddl/db_test.go
+++ b/ddl/db_test.go
@@ -123,6 +123,10 @@ func setUpSuite(s *testDBSuite, c *C) {
 	c.Assert(err, IsNil)
 	_, err = s.s.Execute(context.Background(), "set @@global.tidb_max_delta_schema_count= 4096")
 	c.Assert(err, IsNil)
+	_, err = s.s.Execute(context.Background(), "set @@global.tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
+	_, err = s.s.Execute(context.Background(), "set @@tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
 }
 
 func tearDownSuite(s *testDBSuite, c *C) {
diff --git a/executor/executor_test.go b/executor/executor_test.go
index 7cb72b266e263..eef914d9de15d 100644
--- a/executor/executor_test.go
+++ b/executor/executor_test.go
@@ -202,6 +202,13 @@ func (s *baseTestSuite) SetUpSuite(c *C) {
 	}
 	d, err := session.BootstrapSession(s.store)
 	c.Assert(err, IsNil)
+	se, err := session.CreateSession4Test(s.store)
+	c.Assert(err, IsNil)
+	// Set the variable to default 0 as it was before in case of modifying the test.
+	_, err = se.Execute(context.Background(), "set @@global.tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
+	_, err = se.Execute(context.Background(), "set @@tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
 	d.SetStatsUpdating(true)
 	s.domain = d
 	config.UpdateGlobal(func(conf *config.Config) {
diff --git a/expression/integration_test.go b/expression/integration_test.go
index 1cf17e1d36bfa..cc1b160c405e3 100644
--- a/expression/integration_test.go
+++ b/expression/integration_test.go
@@ -94,6 +94,13 @@ func (s *testIntegrationSuiteBase) SetUpSuite(c *C) {
 	s.store, s.dom, err = newStoreWithBootstrap()
 	c.Assert(err, IsNil)
 	s.ctx = mock.NewContext()
+	se, err := session.CreateSession4Test(s.store)
+	c.Assert(err, IsNil)
+	// Set the variable to default 0 as it was before in case of modifying the test.
+	_, err = se.Execute(context.Background(), "set @@global.tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
+	_, err = se.Execute(context.Background(), "set @@tidb_enable_change_column_type=0")
+	c.Assert(err, IsNil)
 }
 
 func (s *testIntegrationSuiteBase) TearDownSuite(c *C) {
diff --git a/sessionctx/variable/tidb_vars.go b/sessionctx/variable/tidb_vars.go
index e93414bc5e26e..d9c23a0d49b48 100644
--- a/sessionctx/variable/tidb_vars.go
+++ b/sessionctx/variable/tidb_vars.go
@@ -650,7 +650,7 @@ const (
 	DefTiDBDDLReorgBatchSize           = 256
 	DefTiDBDDLErrorCountLimit          = 512
 	DefTiDBMaxDeltaSchemaCount         = 1024
-	DefTiDBChangeColumnType            = false
+	DefTiDBChangeColumnType            = true
 	DefTiDBChangeMultiSchema           = false
 	DefTiDBPointGetCache               = false
 	DefTiDBEnableAlterPlacement        = false