diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index 564edeaddd..7904cd355c 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1016,7 +1016,7 @@ class Application(QApplication):
         try:
             if self.clipboard().ownsClipboard():
                 import ctypes
-                ctypes.WinDLL(b'ole32.dll').OleFlushClipboard()
+                ctypes.WinDLL('ole32.dll').OleFlushClipboard()
         except Exception:
             import traceback
             traceback.print_exc()