diff --git a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
index 047a548..a48a68c 100644
--- a/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
+++ b/src/main/scala/gitbucket/core/controller/RepositoryViewerController.scala
@@ -938,10 +938,10 @@
                 context.settings.repositoryViewer.maxFiles
               )
               val parentPath = if (path == ".") Nil else path.split("/").toList
-              // process README.md or README.markdown
-              val readme = files
+              // process README
+              val readme = files // files should be sorted alphabetically.
                 .find { file =>
-                  !file.isDirectory && readmeFiles.contains(file.name.toLowerCase)
+                  !file.isDirectory && RepositoryService.readmeFiles.contains(file.name.toLowerCase)
                 }
                 .map { file =>
                   val path = (file.name :: parentPath.reverse).reverse
diff --git a/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala b/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala
index 6559e38..519568c 100644
--- a/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala
+++ b/src/main/scala/gitbucket/core/controller/api/ApiRepositoryContentsControllerBase.scala
@@ -23,9 +23,12 @@
     Using.resource(Git.open(getRepositoryDir(params("owner"), params("repository")))) {
       git =>
         val refStr = params.getOrElse("ref", repository.repository.defaultBranch)
-        val fileList = getFileList(git, refStr, ".", maxFiles = context.settings.repositoryViewer.maxFiles)
-        fileList.map(f => f.name).find(p => readmeFiles.map(_.toLowerCase).contains(p.toLowerCase)) match {
-          case Some(x) => getContents(repository = repository, path = x, refStr = refStr, ignoreCase = true)
+        val files = getFileList(git, refStr, ".", maxFiles = context.settings.repositoryViewer.maxFiles)
+        files // files should be sorted alphabetically.
+          .find { file =>
+            !file.isDirectory && RepositoryService.readmeFiles.contains(file.name.toLowerCase)
+          } match {
+          case Some(x) => getContents(repository = repository, path = x.name, refStr = refStr, ignoreCase = true)
           case _       => NotFound()
         }
     }
diff --git a/src/main/scala/gitbucket/core/service/RepositoryCommitFileService.scala b/src/main/scala/gitbucket/core/service/RepositoryCommitFileService.scala
index 9dbee15..6a0f651 100644
--- a/src/main/scala/gitbucket/core/service/RepositoryCommitFileService.scala
+++ b/src/main/scala/gitbucket/core/service/RepositoryCommitFileService.scala
@@ -116,11 +116,6 @@
     }
   }
 
-  def readmeFiles: Seq[String] =
-    PluginRegistry().renderableExtensions.map { extension =>
-      s"readme.${extension}"
-    } ++ Seq("readme.txt", "readme")
-
   private def _commitFile(
     repository: RepositoryService.RepositoryInfo,
     branch: String,
diff --git a/src/main/scala/gitbucket/core/service/RepositoryService.scala b/src/main/scala/gitbucket/core/service/RepositoryService.scala
index dcf9f11..831820e 100644
--- a/src/main/scala/gitbucket/core/service/RepositoryService.scala
+++ b/src/main/scala/gitbucket/core/service/RepositoryService.scala
@@ -839,4 +839,9 @@
     } else None
   def openRepoUrl(openUrl: String)(implicit context: Context): String =
     s"github-${context.platform}://openRepo/${openUrl}"
+
+  def readmeFiles: Seq[String] =
+    PluginRegistry().renderableExtensions.map { extension =>
+      s"readme.${extension}"
+    } ++ Seq("readme.txt", "readme")
 }