diff --git a/src/main/scala/gitbucket/core/controller/FileUploadController.scala b/src/main/scala/gitbucket/core/controller/FileUploadController.scala
index c3503ac..8b118d8 100644
--- a/src/main/scala/gitbucket/core/controller/FileUploadController.scala
+++ b/src/main/scala/gitbucket/core/controller/FileUploadController.scala
@@ -17,22 +17,22 @@
   configureMultipartHandling(MultipartConfig(maxFileSize = Some(3 * 1024 * 1024)))
 
   post("/image"){
-    execute { (file, fileId) =>
+    execute({ (file, fileId) =>
       FileUtils.writeByteArrayToFile(new java.io.File(getTemporaryDir(session.getId), fileId), file.get)
       session += Keys.Session.Upload(fileId) -> file.name
-    }
+    }, FileUtil.isImage)
   }
 
   post("/image/:owner/:repository"){
-    execute { (file, fileId) =>
+    execute({ (file, fileId) =>
       FileUtils.writeByteArrayToFile(new java.io.File(
         getAttachedDir(params("owner"), params("repository")),
         fileId + "." + FileUtil.getExtension(file.getName)), file.get)
-    }
+    }, FileUtil.isUploadableType)
   }
 
-  private def execute(f: (FileItem, String) => Unit) = fileParams.get("file") match {
-    case Some(file) if(FileUtil.isImage(file.name)) =>
+  private def execute(f: (FileItem, String) => Unit, mimeTypeChcker: (String) => Boolean) = fileParams.get("file") match {
+    case Some(file) if(mimeTypeChcker(file.name)) =>
       defining(FileUtil.generateFileId){ fileId =>
         f(file, fileId)
 
diff --git a/src/main/scala/gitbucket/core/util/FileUtil.scala b/src/main/scala/gitbucket/core/util/FileUtil.scala
index d3428fb..8dd8aae 100644
--- a/src/main/scala/gitbucket/core/util/FileUtil.scala
+++ b/src/main/scala/gitbucket/core/util/FileUtil.scala
@@ -28,6 +28,12 @@
 
   def isImage(name: String): Boolean = getMimeType(name).startsWith("image/")
 
+  def isUploadableType(name: String): Boolean = getMimeType(name) match {
+    case t if t.startsWith("image/") => true
+    case "application/pdf" => true
+    case _ => false
+  }
+
   def isLarge(size: Long): Boolean = (size > 1024 * 1000)
 
   def isText(content: Array[Byte]): Boolean = !content.contains(0)
diff --git a/src/main/twirl/gitbucket/core/helper/attached.scala.html b/src/main/twirl/gitbucket/core/helper/attached.scala.html
index 33bd58e..7bb4726 100644
--- a/src/main/twirl/gitbucket/core/helper/attached.scala.html
+++ b/src/main/twirl/gitbucket/core/helper/attached.scala.html
@@ -11,7 +11,7 @@
     $([$('#@textareaId').closest('div')[0], $('#@textareaId').next('div')[0]]).dropzone({
       url: '@path/upload/image/@owner/@repository',
       maxFilesize: 10,
-      acceptedFiles: 'image/*',
+      acceptedFiles: 'image/*,application/pdf',
       dictInvalidFileType: 'Unfortunately, we don\'t support that file type. Try again with a PNG, GIF, or JPG.',
       previewTemplate: "<div class=\"dz-preview\">\n  <div class=\"dz-progress\"><span class=\"dz-upload\" data-dz-uploadprogress>Uploading your images...</span></div>\n  <div class=\"dz-error-message\"><span data-dz-errormessage></span></div>\n</div>",
       success: function(file, id) {