diff --git a/db/alter.go b/db/alter.go
index 14e92ac..782ea7f 100644
--- a/db/alter.go
+++ b/db/alter.go
@@ -1,73 +1,73 @@
 package db
 
 import (
 	"fmt"
 	"strings"
 )
 
 type alterTableQueryType int
 
 const (
 	alter  alterTableQueryType = iota
 	update alterTableQueryType = iota
 )
 
 type change struct {
 	queryType   alterTableQueryType
 	queryString string
 }
 
 type AlterTableSqlBuilder struct {
 	Dialect DialectType
 	Name    string
 	Changes []change
 }
 
 func (b *AlterTableSqlBuilder) AddColumn(col *Column) *AlterTableSqlBuilder {
 	if colVal, err := col.String(); err == nil {
 		b.Changes = append(b.Changes, change{queryType: alter, queryString: fmt.Sprintf("ADD COLUMN %s", colVal)})
 	}
 	return b
 }
 
 func (b *AlterTableSqlBuilder) ChangeColumn(name string, col *Column) *AlterTableSqlBuilder {
 	if colVal, err := col.String(); err == nil {
 		b.Changes = append(b.Changes, change{queryType: alter, queryString: fmt.Sprintf("RENAME COLUMN %s TO %s_old", name, name)})
 		b.Changes = append(b.Changes, change{queryType: alter, queryString: fmt.Sprintf("ADD COLUMN %s", colVal)})
 		b.Changes = append(b.Changes, change{queryType: update, queryString: fmt.Sprintf("SET %s = %s_old", col.Name, name)})
-		b.Changes = append(b.Changes, change{queryType: alter, queryString: fmt.Sprintf("DROP COLUMN %s", name)})
+		b.Changes = append(b.Changes, change{queryType: alter, queryString: fmt.Sprintf("DROP COLUMN %s_old", name)})
 	}
 	return b
 }
 
 func (b *AlterTableSqlBuilder) AddUniqueConstraint(name string, columns ...string) *AlterTableSqlBuilder {
 	b.Changes = append(b.Changes, change{
 		queryType: alter,
 		queryString: fmt.Sprintf("ADD CONSTRAINT %s UNIQUE (%s)", name, strings.Join(columns, ", ")),
 	})
 	return b
 }
 
 func (b *AlterTableSqlBuilder) ToSQL() (string, error) {
 	str := ""
 	changeCount := len(b.Changes)
 
 	if changeCount == 0 {
 		return "", fmt.Errorf("no changes provide for table: %s", b.Name)
 	}
 
 	for i, change := range b.Changes {
 		switch change.queryType {
 		case alter:
 			str += fmt.Sprintf("ALTER TABLE %s ", b.Name)
 		case update:
 			str += fmt.Sprintf("UPDATE %s ", b.Name)
 		}
 		str += change.queryString
 		if i < changeCount - 1 {
 			str += "; "
 		}
 	}
 
 	return str, nil
 }