diff --git a/integrations/change_default_branch_test.go b/integrations/change_default_branch_test.go
new file mode 100644
index 00000000000..03ece46a58f
--- /dev/null
+++ b/integrations/change_default_branch_test.go
@@ -0,0 +1,58 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package integrations
+
+import (
+	"bytes"
+	"fmt"
+	"net/http"
+	"net/url"
+	"testing"
+
+	"code.gitea.io/gitea/models"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestChangeDefaultBranch(t *testing.T) {
+	prepareTestEnv(t)
+	repo := models.AssertExistsAndLoadBean(t, &models.Repository{ID: 1}).(*models.Repository)
+	owner := models.AssertExistsAndLoadBean(t, &models.User{ID: repo.OwnerID}).(*models.User)
+
+	session := loginUser(t, owner.Name, "password")
+	branchesURL := fmt.Sprintf("/%s/%s/settings/branches", owner.Name, repo.Name)
+
+	req := NewRequest(t, "GET", branchesURL)
+	resp := session.MakeRequest(t, req)
+	assert.EqualValues(t, http.StatusOK, resp.HeaderCode)
+	doc, err := NewHtmlParser(resp.Body)
+	assert.NoError(t, err)
+
+	req = NewRequestBody(t, "POST", branchesURL,
+		bytes.NewBufferString(url.Values{
+			"_csrf":  []string{doc.GetInputValueByName("_csrf")},
+			"action": []string{"default_branch"},
+			"branch": []string{"DefaultBranch"},
+		}.Encode()))
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	resp = session.MakeRequest(t, req)
+	assert.EqualValues(t, http.StatusFound, resp.HeaderCode)
+
+	req = NewRequest(t, "GET", branchesURL)
+	resp = session.MakeRequest(t, req)
+	assert.EqualValues(t, http.StatusOK, resp.HeaderCode)
+	doc, err = NewHtmlParser(resp.Body)
+	assert.NoError(t, err)
+
+	req = NewRequestBody(t, "POST", branchesURL,
+		bytes.NewBufferString(url.Values{
+			"_csrf":  []string{doc.GetInputValueByName("_csrf")},
+			"action": []string{"default_branch"},
+			"branch": []string{"does_not_exist"},
+		}.Encode()))
+	req.Header.Add("Content-Type", "application/x-www-form-urlencoded")
+	resp = session.MakeRequest(t, req)
+	assert.EqualValues(t, http.StatusNotFound, resp.HeaderCode)
+}
diff --git a/integrations/gitea-integration-meta/gitea-repositories/user2/repo1.git/refs/heads/DefaultBranch b/integrations/gitea-integration-meta/gitea-repositories/user2/repo1.git/refs/heads/DefaultBranch
new file mode 100644
index 00000000000..f98a263be62
--- /dev/null
+++ b/integrations/gitea-integration-meta/gitea-repositories/user2/repo1.git/refs/heads/DefaultBranch
@@ -0,0 +1 @@
+65f1bf27bc3bf70f64657658635e66094edbcb4d
diff --git a/integrations/gitea-integration-meta/gitea-repositories/user2/repo1.git/refs/heads/develop b/integrations/gitea-integration-meta/gitea-repositories/user2/repo1.git/refs/heads/develop
new file mode 100644
index 00000000000..f98a263be62
--- /dev/null
+++ b/integrations/gitea-integration-meta/gitea-repositories/user2/repo1.git/refs/heads/develop
@@ -0,0 +1 @@
+65f1bf27bc3bf70f64657658635e66094edbcb4d
diff --git a/routers/repo/setting.go b/routers/repo/setting.go
index b2cb73cf98f..a50c6a6e227 100644
--- a/routers/repo/setting.go
+++ b/routers/repo/setting.go
@@ -480,9 +480,11 @@ func ProtectedBranchPost(ctx *context.Context) {
 			return
 		}
 
-		branch := strings.ToLower(ctx.Query("branch"))
-		if ctx.Repo.GitRepo.IsBranchExist(branch) &&
-			repo.DefaultBranch != branch {
+		branch := ctx.Query("branch")
+		if !ctx.Repo.GitRepo.IsBranchExist(branch) {
+			ctx.Status(404)
+			return
+		} else if repo.DefaultBranch != branch {
 			repo.DefaultBranch = branch
 			if err := ctx.Repo.GitRepo.SetDefaultBranch(branch); err != nil {
 				if !git.IsErrUnsupportedVersion(err) {