diff --git a/SilicaViewer/ExportAccessoryView.swift b/SilicaViewer/ExportAccessoryView.swift
index d779524..3cc90e9 100644
--- a/SilicaViewer/ExportAccessoryView.swift
+++ b/SilicaViewer/ExportAccessoryView.swift
@@ -1,5 +1,6 @@
 import Foundation
 import AppKit
+import UniformTypeIdentifiers
 
 class ExportAccessoryView : NSView {
     
@@ -18,7 +19,11 @@ class ExportAccessoryView : NSView {
     }
     
     @IBAction func changeFileFormat(_ sender: Any) {
-        savePanel?.allowedFileTypes?.removeAll()
-        savePanel?.allowedFileTypes?.append((typeBox.titleOfSelectedItem?.lowercased())!)
+        if #available(macOS 11.0, *) {
+            savePanel?.allowedContentTypes = [UTType(filenameExtension: (typeBox.titleOfSelectedItem?.lowercased())!)!]
+        } else {
+            savePanel?.allowedFileTypes?.removeAll()
+            savePanel?.allowedFileTypes?.append((typeBox.titleOfSelectedItem?.lowercased())!)
+        };
     }
 }