diff --git a/src/calibre/gui2/__init__.py b/src/calibre/gui2/__init__.py
index a56acfc9aa..7fe34c7ef8 100644
--- a/src/calibre/gui2/__init__.py
+++ b/src/calibre/gui2/__init__.py
@@ -1145,6 +1145,8 @@ def open_url(qurl):
 
 
 def safe_open_url(qurl):
+    if isinstance(qurl, string_or_bytes):
+        qurl = QUrl(qurl)
     if qurl.scheme() in ('', 'file'):
         path = qurl.toLocalFile()
         ext = os.path.splitext(path)[-1].lower()[1:]