diff --git a/project/build.scala b/project/build.scala
index 1337898..3034720 100644
--- a/project/build.scala
+++ b/project/build.scala
@@ -56,6 +56,7 @@
       "org.apache.commons" % "commons-email" % "1.3.3",
       "org.apache.httpcomponents" % "httpclient" % "4.3.6",
       "org.apache.sshd" % "apache-sshd" % "0.11.0",
+      "org.apache.tika" % "tika-core" % "1.10",
       "com.typesafe.slick" %% "slick" % "2.1.0",
       "com.novell.ldap" % "jldap" % "2009-10-07",
       "com.h2database" % "h2" % "1.4.180",
diff --git a/src/main/scala/gitbucket/core/util/FileUtil.scala b/src/main/scala/gitbucket/core/util/FileUtil.scala
index 8dd8aae..f753a60 100644
--- a/src/main/scala/gitbucket/core/util/FileUtil.scala
+++ b/src/main/scala/gitbucket/core/util/FileUtil.scala
@@ -1,7 +1,7 @@
 package gitbucket.core.util
 
 import org.apache.commons.io.FileUtils
-import java.net.URLConnection
+import org.apache.tika.Tika
 import java.io.File
 import ControlUtil._
 import scala.util.Random
@@ -9,8 +9,8 @@
 object FileUtil {
 
   def getMimeType(name: String): String =
-    defining(URLConnection.getFileNameMap()){ fileNameMap =>
-      fileNameMap.getContentTypeFor(name) match {
+    defining(new Tika()){ tika =>
+      tika.detect(name) match {
         case null     => "application/octet-stream"
         case mimeType => mimeType
       }
@@ -28,11 +28,7 @@
 
   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 isUploadableType(name: String): Boolean = mimeTypeWhiteList contains getMimeType(name)
 
   def isLarge(size: Long): Boolean = (size > 1024 * 1000)
 
@@ -56,4 +52,14 @@
       FileUtils.deleteDirectory(dir)
     }
   }
+
+  val mimeTypeWhiteList: Array[String] = Array(
+      "application/pdf",
+      "application/vnd.openxmlformats-officedocument.presentationml.presentation",
+      "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet",
+      "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+      "image/gif",
+      "image/jpeg",
+      "image/png",
+      "text/plain")
 }
diff --git a/src/main/twirl/gitbucket/core/helper/attached.scala.html b/src/main/twirl/gitbucket/core/helper/attached.scala.html
index 94b5af8..b961c8e 100644
--- a/src/main/twirl/gitbucket/core/helper/attached.scala.html
+++ b/src/main/twirl/gitbucket/core/helper/attached.scala.html
@@ -1,5 +1,6 @@
 @(owner: String, repository: String)(textarea: Html)(implicit context: gitbucket.core.controller.Context)
 @import context._
+@import gitbucket.core.util.FileUtil
 <div class="muted attachable">
   @textarea
   <div class="clickable">Attach images or PDF files by dragging &amp; dropping, or selecting them.</div>
@@ -11,7 +12,7 @@
     $([$('#@textareaId').closest('div')[0], $('#@textareaId').next('div')[0]]).dropzone({
       url: '@path/upload/file/@owner/@repository',
       maxFilesize: 10,
-      acceptedFiles: 'image/*,application/pdf',
+      acceptedFiles: @Html(FileUtil.mimeTypeWhiteList.mkString("'", ",", "'")),
       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 or PDF files...</span></div>\n  <div class=\"dz-error-message\"><span data-dz-errormessage></span></div>\n</div>",
       success: function(file, id) {