diff --git a/modules/base/natural_sort.go b/modules/base/natural_sort.go
index e920177f8..5b5febb90 100644
--- a/modules/base/natural_sort.go
+++ b/modules/base/natural_sort.go
@@ -5,11 +5,13 @@ package base
 
 import (
 	"math/big"
+	"strings"
 	"unicode/utf8"
 )
 
 // NaturalSortLess compares two strings so that they could be sorted in natural order
 func NaturalSortLess(s1, s2 string) bool {
+	s1, s2 = strings.ToLower(s1), strings.ToLower(s2)
 	var i1, i2 int
 	for {
 		rune1, j1, end1 := getNextRune(s1, i1)
diff --git a/modules/base/natural_sort_test.go b/modules/base/natural_sort_test.go
index 91e864ad2..7378d9a64 100644
--- a/modules/base/natural_sort_test.go
+++ b/modules/base/natural_sort_test.go
@@ -20,4 +20,10 @@ func TestNaturalSortLess(t *testing.T) {
 	test("a-1-a", "a-1-b", true)
 	test("2", "12", true)
 	test("a", "ab", true)
+
+	// Test for case insensitive.
+	test("A", "ab", true)
+	test("B", "ab", false)
+	test("a", "AB", true)
+	test("b", "AB", false)
 }
diff --git a/tests/integration/repo_test.go b/tests/integration/repo_test.go
index b62297e0e..03124ecaf 100644
--- a/tests/integration/repo_test.go
+++ b/tests/integration/repo_test.go
@@ -6,6 +6,7 @@ package integration
 import (
 	"fmt"
 	"net/http"
+	"net/url"
 	"path"
 	"strings"
 	"testing"
@@ -15,11 +16,13 @@ import (
 	repo_model "code.gitea.io/gitea/models/repo"
 	unit_model "code.gitea.io/gitea/models/unit"
 	"code.gitea.io/gitea/models/unittest"
+	user_model "code.gitea.io/gitea/models/user"
 	"code.gitea.io/gitea/modules/git"
 	"code.gitea.io/gitea/modules/setting"
 	"code.gitea.io/gitea/modules/test"
 	"code.gitea.io/gitea/modules/translation"
 	repo_service "code.gitea.io/gitea/services/repository"
+	files_service "code.gitea.io/gitea/services/repository/files"
 	"code.gitea.io/gitea/tests"
 
 	"github.com/PuerkitoBio/goquery"
@@ -899,3 +902,62 @@ func TestRepoHomeViewRedirect(t *testing.T) {
 		assert.Equal(t, "Wiki", txt)
 	})
 }
+
+func TestRepoFilesList(t *testing.T) {
+	onGiteaRun(t, func(t *testing.T, u *url.URL) {
+		user2 := unittest.AssertExistsAndLoadBean(t, &user_model.User{ID: 2})
+
+		// create the repo
+		repo, _, f := CreateDeclarativeRepo(t, user2, "",
+			[]unit_model.Type{unit_model.TypeCode}, nil,
+			[]*files_service.ChangeRepoFile{
+				{
+					Operation:     "create",
+					TreePath:      "zEta",
+					ContentReader: strings.NewReader("zeta"),
+				},
+				{
+					Operation:     "create",
+					TreePath:      "licensa",
+					ContentReader: strings.NewReader("licensa"),
+				},
+				{
+					Operation:     "create",
+					TreePath:      "licensz",
+					ContentReader: strings.NewReader("licensz"),
+				},
+				{
+					Operation:     "create",
+					TreePath:      "delta",
+					ContentReader: strings.NewReader("delta"),
+				},
+				{
+					Operation:     "create",
+					TreePath:      "Charlie/aa.txt",
+					ContentReader: strings.NewReader("charlie"),
+				},
+				{
+					Operation:     "create",
+					TreePath:      "Beta",
+					ContentReader: strings.NewReader("beta"),
+				},
+				{
+					Operation:     "create",
+					TreePath:      "alpha",
+					ContentReader: strings.NewReader("alpha"),
+				},
+			},
+		)
+		defer f()
+
+		req := NewRequest(t, "GET", "/"+repo.FullName())
+		resp := MakeRequest(t, req, http.StatusOK)
+
+		htmlDoc := NewHTMLParser(t, resp.Body)
+		filesList := htmlDoc.Find("#repo-files-table tbody tr").Map(func(_ int, s *goquery.Selection) string {
+			return s.AttrOr("data-entryname", "")
+		})
+
+		assert.EqualValues(t, []string{"Charlie", "alpha", "Beta", "delta", "licensa", "LICENSE", "licensz", "README.md", "zEta"}, filesList)
+	})
+}