diff --git a/models/migrations/migrations_test.go b/models/migrations/migrations_test.go
index 2effcb99e..10ba3dde0 100644
--- a/models/migrations/migrations_test.go
+++ b/models/migrations/migrations_test.go
@@ -8,6 +8,7 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"path"
 	"path/filepath"
@@ -57,6 +58,14 @@ func TestMain(m *testing.M) {
 		setting.CustomConf = giteaConf
 	}
 
+	tmpDataPath, err := ioutil.TempDir("", "data")
+	if err != nil {
+		fmt.Printf("Unable to create temporary data path %v\n", err)
+		os.Exit(1)
+	}
+
+	setting.AppDataPath = tmpDataPath
+
 	setting.SetCustomPathAndConf("", "", "")
 	setting.LoadForTest()
 	git.CheckLFSVersion()
@@ -68,7 +77,7 @@ func TestMain(m *testing.M) {
 	if err := removeAllWithRetry(setting.RepoRootPath); err != nil {
 		fmt.Fprintf(os.Stderr, "os.RemoveAll: %v\n", err)
 	}
-	if err := removeAllWithRetry(setting.AppDataPath); err != nil {
+	if err := removeAllWithRetry(tmpDataPath); err != nil {
 		fmt.Fprintf(os.Stderr, "os.RemoveAll: %v\n", err)
 	}
 	os.Exit(exitStatus)
diff --git a/models/unittest/testdb.go b/models/unittest/testdb.go
index 94c93755e..8083c607e 100644
--- a/models/unittest/testdb.go
+++ b/models/unittest/testdb.go
@@ -67,14 +67,16 @@ func MainTest(m *testing.M, pathToGiteaRoot string, fixtureFiles ...string) {
 	setting.SSH.Port = 3000
 	setting.SSH.Domain = "try.gitea.io"
 	setting.Database.UseSQLite3 = true
-	setting.RepoRootPath, err = os.MkdirTemp(os.TempDir(), "repos")
+	repoRootPath, err := os.MkdirTemp(os.TempDir(), "repos")
 	if err != nil {
 		fatalTestError("TempDir: %v\n", err)
 	}
-	setting.AppDataPath, err = os.MkdirTemp(os.TempDir(), "appdata")
+	setting.RepoRootPath = repoRootPath
+	appDataPath, err := os.MkdirTemp(os.TempDir(), "appdata")
 	if err != nil {
 		fatalTestError("TempDir: %v\n", err)
 	}
+	setting.AppDataPath = appDataPath
 	setting.AppWorkPath = pathToGiteaRoot
 	setting.StaticRootPath = pathToGiteaRoot
 	setting.GravatarSourceURL, err = url.Parse("https://secure.gravatar.com/avatar/")
@@ -95,7 +97,7 @@ func MainTest(m *testing.M, pathToGiteaRoot string, fixtureFiles ...string) {
 		fatalTestError("storage.Init: %v\n", err)
 	}
 
-	if err = util.RemoveAll(setting.RepoRootPath); err != nil {
+	if err = util.RemoveAll(repoRootPath); err != nil {
 		fatalTestError("util.RemoveAll: %v\n", err)
 	}
 	if err = util.CopyDir(filepath.Join(pathToGiteaRoot, "integrations", "gitea-repositories-meta"), setting.RepoRootPath); err != nil {
@@ -103,10 +105,10 @@ func MainTest(m *testing.M, pathToGiteaRoot string, fixtureFiles ...string) {
 	}
 
 	exitStatus := m.Run()
-	if err = util.RemoveAll(setting.RepoRootPath); err != nil {
+	if err = util.RemoveAll(repoRootPath); err != nil {
 		fatalTestError("util.RemoveAll: %v\n", err)
 	}
-	if err = util.RemoveAll(setting.AppDataPath); err != nil {
+	if err = util.RemoveAll(appDataPath); err != nil {
 		fatalTestError("util.RemoveAll: %v\n", err)
 	}
 	os.Exit(exitStatus)
diff --git a/services/mailer/mailer_test.go b/services/mailer/mailer_test.go
index 8505803d2..1739a68a6 100644
--- a/services/mailer/mailer_test.go
+++ b/services/mailer/mailer_test.go
@@ -9,17 +9,16 @@ import (
 	"time"
 
 	"code.gitea.io/gitea/modules/setting"
-
 	"github.com/stretchr/testify/assert"
 )
 
 func TestGenerateMessageID(t *testing.T) {
-	setting.LoadForTest(`
-[mailer]
-ENABLED = true
-FROM = test@domain.com
-`)
-	setting.NewServices()
+	var mailService = setting.Mailer{
+		From: "test@gitea.com",
+	}
+
+	setting.MailService = &mailService
+	setting.Domain = "localhost"
 
 	date := time.Date(2000, 01, 02, 03, 04, 05, 06, time.UTC)
 	m := NewMessageFrom(nil, "display-name", "from-address", "subject", "body")