diff --git a/server/access-file.c b/server/access-file.c
index 454f965..23b99e2 100644
--- a/server/access-file.c
+++ b/server/access-file.c
@@ -123,11 +123,11 @@ extern SeafileSession *seaf;
 static struct file_type_map ftmap[] = {
     { "txt", "text/plain" },
     { "doc", "application/vnd.ms-word" },
-    { "docx", "application/vnd.ms-word" },
+    { "docx", "application/vnd.openxmlformats-officedocument.wordprocessingml.document" },
     { "ppt", "application/vnd.ms-powerpoint" },
-    { "pptx", "application/vnd.ms-powerpoint" },
+    { "pptx", "application/vnd.openxmlformats-officedocument.presentationml.presentation" },
     { "xls", "application/vnd.ms-excel" },
-    { "xlsx", "application/vnd.ms-excel" },
+    { "xlsx", "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet" },
     { "pdf", "application/pdf" },
     { "zip", "application/zip"},
     { "mp3", "audio/mp3" },