diff --git a/models/migrations/v15.go b/models/migrations/v15.go
index e29067c98..3492a7190 100644
--- a/models/migrations/v15.go
+++ b/models/migrations/v15.go
@@ -10,21 +10,15 @@ import (
 	"github.com/go-xorm/xorm"
 )
 
-// UserV15 describes the added field for User
-type UserV15 struct {
-	KeepEmailPrivate        bool
-	AllowCreateOrganization bool
-}
-
-// TableName will be invoked by XORM to customrize the table name
-func (*UserV15) TableName() string {
-	return "user"
-}
-
 func createAllowCreateOrganizationColumn(x *xorm.Engine) error {
-	if err := x.Sync2(new(UserV15)); err != nil {
+	type User struct {
+		KeepEmailPrivate        bool
+		AllowCreateOrganization bool
+	}
+
+	if err := x.Sync2(new(User)); err != nil {
 		return fmt.Errorf("Sync2: %v", err)
-	} else if _, err = x.Where("type=0").Cols("allow_create_organization").Update(&UserV15{AllowCreateOrganization: true}); err != nil {
+	} else if _, err = x.Where("`type` = 0").Cols("allow_create_organization").Update(&User{AllowCreateOrganization: true}); err != nil {
 		return fmt.Errorf("set allow_create_organization: %v", err)
 	}
 	return nil
diff --git a/models/migrations/v16.go b/models/migrations/v16.go
index f14b196f2..f6fb76da5 100644
--- a/models/migrations/v16.go
+++ b/models/migrations/v16.go
@@ -33,9 +33,9 @@ func addUnitsToTables(x *xorm.Engine) error {
 		RepoID      int64 `xorm:"INDEX(s)"`
 		Type        int   `xorm:"INDEX(s)"`
 		Index       int
-		Config      map[string]string `xorm:"JSON"`
-		CreatedUnix int64             `xorm:"INDEX CREATED"`
-		Created     time.Time         `xorm:"-"`
+		Config      map[string]interface{} `xorm:"JSON"`
+		CreatedUnix int64                  `xorm:"INDEX CREATED"`
+		Created     time.Time              `xorm:"-"`
 	}
 
 	// Repo describes a repository
@@ -95,7 +95,7 @@ func addUnitsToTables(x *xorm.Engine) error {
 				continue
 			}
 
-			var config = make(map[string]string)
+			var config = make(map[string]interface{})
 			switch i {
 			case V16UnitTypeExternalTracker:
 				config["ExternalTrackerURL"] = repo.ExternalTrackerURL
diff --git a/models/migrations/v37.go b/models/migrations/v37.go
index aac00e84c..00653a780 100644
--- a/models/migrations/v37.go
+++ b/models/migrations/v37.go
@@ -7,16 +7,19 @@ package migrations
 import (
 	"html"
 
-	"code.gitea.io/gitea/models"
-
 	"github.com/go-xorm/xorm"
 )
 
 func unescapeUserFullNames(x *xorm.Engine) (err error) {
+	type User struct {
+		ID       int64 `xorm:"pk autoincr"`
+		FullName string
+	}
+
 	const batchSize = 100
 	for start := 0; ; start += batchSize {
-		users := make([]*models.User, 0, batchSize)
-		if err := x.Limit(start, batchSize).Find(users); err != nil {
+		users := make([]*User, 0, batchSize)
+		if err := x.Limit(batchSize, start).Find(&users); err != nil {
 			return err
 		}
 		if len(users) == 0 {
@@ -24,7 +27,7 @@ func unescapeUserFullNames(x *xorm.Engine) (err error) {
 		}
 		for _, user := range users {
 			user.FullName = html.UnescapeString(user.FullName)
-			if _, err := x.Cols("full_name").Update(user); err != nil {
+			if _, err := x.ID(user.ID).Cols("full_name").Update(user); err != nil {
 				return err
 			}
 		}
diff --git a/models/migrations/v38.go b/models/migrations/v38.go
index 216d49935..6f66484b0 100644
--- a/models/migrations/v38.go
+++ b/models/migrations/v38.go
@@ -47,7 +47,7 @@ func removeCommitsUnitType(x *xorm.Engine) (err error) {
 				}
 			}
 			team.UnitTypes = ut
-			if _, err := x.Id(team.ID).Cols("unit_types").Update(team); err != nil {
+			if _, err := x.ID(team.ID).Cols("unit_types").Update(team); err != nil {
 				return err
 			}
 		}