diff --git a/dialects/postgresql/builder_test.go b/dialects/postgresql/builder_test.go
index efdd33a..4db1e4a 100644
--- a/dialects/postgresql/builder_test.go
+++ b/dialects/postgresql/builder_test.go
@@ -71,6 +71,26 @@ func TestAlterTableAddColumn(t *testing.T) {
 	expectedSQL := "ALTER TABLE \"user\" ADD COLUMN \"updated_at\" TIMESTAMP(6);"
 	returnedSQL := sqlBuilder.AlterTableAddColumn(userTableName, updatedAtColumn)
 	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	createdAtColumn := testutils.FakeCreatedAtColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"created_at\" TIMESTAMPZ(6) NOT NULL DEFAULT CURRENT_TIMESTAMP;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, createdAtColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	priceColumn := testutils.FakePriceColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"price\" NUMERIC(17,2) NOT NULL DEFAULT 0.0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, priceColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	scoreColumn := testutils.FakeScoreColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"score\" BIGINT NOT NULL DEFAULT 0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, scoreColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	nameColumn := testutils.FakeNameColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"name\" VARCHAR(50) NOT NULL DEFAULT '';"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, nameColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
 }
 
 func TestAlterTableDropColumn(t *testing.T) {
diff --git a/dialects/sqlite/builder_test.go b/dialects/sqlite/builder_test.go
index acc5a5c..856082a 100644
--- a/dialects/sqlite/builder_test.go
+++ b/dialects/sqlite/builder_test.go
@@ -51,6 +51,26 @@ func TestAlterTableAddColumn(t *testing.T) {
 	expectedSQL := "ALTER TABLE \"user\" ADD COLUMN \"updated_at\" DATETIME;"
 	returnedSQL := sqlBuilder.AlterTableAddColumn(userTableName, updatedAtColumn)
 	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	createdAtColumn := testutils.FakeCreatedAtColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"created_at\" DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, createdAtColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	priceColumn := testutils.FakePriceColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"price\" REAL NOT NULL DEFAULT 0.0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, priceColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	scoreColumn := testutils.FakeScoreColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"score\" INTEGER NOT NULL DEFAULT 0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, scoreColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	nameColumn := testutils.FakeNameColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"name\" TEXT NOT NULL DEFAULT '';"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, nameColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
 }
 
 func TestAlterTableDropColumn(t *testing.T) {
diff --git a/dialects/sqlserver/builder_test.go b/dialects/sqlserver/builder_test.go
index 9112d3d..7b86e6c 100644
--- a/dialects/sqlserver/builder_test.go
+++ b/dialects/sqlserver/builder_test.go
@@ -51,6 +51,26 @@ func TestAlterTableAddColumn(t *testing.T) {
 	expectedSQL := "ALTER TABLE [user] ADD COLUMN [updated_at] DATETIME2(6);"
 	returnedSQL := sqlBuilder.AlterTableAddColumn(userTableName, updatedAtColumn)
 	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	createdAtColumn := testutils.FakeCreatedAtColumn(t)
+	expectedSQL = "ALTER TABLE [user] ADD COLUMN [created_at] DATETIMEOFFSET(6) NOT NULL DEFAULT CURRENT_TIMESTAMP;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, createdAtColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	priceColumn := testutils.FakePriceColumn(t)
+	expectedSQL = "ALTER TABLE [user] ADD COLUMN [price] MONEY NOT NULL DEFAULT 0.0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, priceColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	scoreColumn := testutils.FakeScoreColumn(t)
+	expectedSQL = "ALTER TABLE [user] ADD COLUMN [score] BIGINT NOT NULL DEFAULT 0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, scoreColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	nameColumn := testutils.FakeNameColumn(t)
+	expectedSQL = "ALTER TABLE [user] ADD COLUMN [name] VARCHAR(50) NOT NULL DEFAULT '';"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, nameColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
 }
 
 func TestAlterTableDropColumn(t *testing.T) {
diff --git a/internal/builder_generic.go b/internal/builder_generic.go
index 1bcd96b..9daf675 100644
--- a/internal/builder_generic.go
+++ b/internal/builder_generic.go
@@ -64,7 +64,21 @@ func (sb *genericSQLBuilder) DropTable(table string) string {
 }
 
 func (sb *genericSQLBuilder) AlterTableAddColumn(table string, column schema.Column) string {
-	return fmt.Sprintf("ALTER TABLE %s ADD COLUMN %s;", sb.QuoteIdentifier(table), sb.columnDefinition(column))
+	defaultValue := ""
+	if column.NotNull() {
+		defaultValue = " DEFAULT "
+		switch column.Type() {
+		case schema.Boolean, schema.Integer:
+			defaultValue += "0"
+		case schema.DateTime, schema.DateTimeOffSet:
+			defaultValue += "CURRENT_TIMESTAMP"
+		case schema.Monetary, schema.Decimal:
+			defaultValue += "0.0"
+		default:
+			defaultValue += "''"
+		}
+	}
+	return fmt.Sprintf("ALTER TABLE %s ADD COLUMN %s%s;", sb.QuoteIdentifier(table), sb.columnDefinition(column), defaultValue)
 }
 
 func (sb *genericSQLBuilder) AlterTableDropColumn(table, column string) string {
diff --git a/internal/builder_generic_test.go b/internal/builder_generic_test.go
index 854ea19..6cbbcac 100644
--- a/internal/builder_generic_test.go
+++ b/internal/builder_generic_test.go
@@ -39,10 +39,31 @@ func TestAlterTableAddColumn(t *testing.T) {
 	sqlBuilder := internal.NewGenericSQLBuilder(nil, nil, nil)
 
 	userTableName := testutils.FakeUserTableName(t)
+
 	updatedAtColumn := testutils.FakeUpdatedAtColumn(t)
 	expectedSQL := "ALTER TABLE \"user\" ADD COLUMN \"updated_at\" <<TYPE_3>>;"
 	returnedSQL := sqlBuilder.AlterTableAddColumn(userTableName, updatedAtColumn)
 	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	createdAtColumn := testutils.FakeCreatedAtColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"created_at\" <<TYPE_7>> DEFAULT CURRENT_TIMESTAMP;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, createdAtColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	priceColumn := testutils.FakePriceColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"price\" <<TYPE_2>> DEFAULT 0.0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, priceColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	scoreColumn := testutils.FakeScoreColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"score\" <<TYPE_0>> DEFAULT 0;"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, scoreColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
+
+	nameColumn := testutils.FakeNameColumn(t)
+	expectedSQL = "ALTER TABLE \"user\" ADD COLUMN \"name\" <<TYPE_1>> DEFAULT '';"
+	returnedSQL = sqlBuilder.AlterTableAddColumn(userTableName, nameColumn)
+	testutils.AssertEqualWithLabel(t, expectedSQL, returnedSQL, "SQLBuilder.AlterTableAddColumn")
 }
 
 func TestAlterTableDropColumn(t *testing.T) {
diff --git a/internal/testutils/fake.go b/internal/testutils/fake.go
index 1c90bc5..25691dc 100644
--- a/internal/testutils/fake.go
+++ b/internal/testutils/fake.go
@@ -157,6 +157,47 @@ func FakeUpdatedAtColumn(t *testing.T) schema.Column {
 	return updatedAtColumn
 }
 
+func FakeCreatedAtColumn(t *testing.T) schema.Column {
+	return schema.NewColumn(schema.NewColumnParams{
+		Name:          "created_at",
+		Type:          schema.DateTimeOffSet,
+		PrimaryKey:    false,
+		NotNull:       true,
+		AutoIncrement: false,
+	})
+}
+
+func FakeScoreColumn(t *testing.T) schema.Column {
+	return schema.NewColumn(schema.NewColumnParams{
+		Name:          "score",
+		Type:          schema.Integer,
+		PrimaryKey:    false,
+		NotNull:       true,
+		AutoIncrement: false,
+	})
+}
+
+func FakePriceColumn(t *testing.T) schema.Column {
+	return schema.NewColumn(schema.NewColumnParams{
+		Name:          "price",
+		Type:          schema.Monetary,
+		PrimaryKey:    false,
+		NotNull:       true,
+		AutoIncrement: false,
+	})
+}
+
+func FakeNameColumn(t *testing.T) schema.Column {
+	return schema.NewColumn(schema.NewColumnParams{
+		Name:          "name",
+		Type:          schema.Varchar,
+		Size:          50,
+		PrimaryKey:    false,
+		NotNull:       true,
+		AutoIncrement: false,
+	})
+}
+
 func FakeUpdatedAtColumnName(t *testing.T) string {
 	return "updated_at"
 }