diff --git a/src/calibre/prints.py b/src/calibre/prints.py
index 26f69eb821..0b737aff32 100644
--- a/src/calibre/prints.py
+++ b/src/calibre/prints.py
@@ -18,6 +18,8 @@ def is_binary(stream):
 def prints(*a, **kw):
     ' Print either unicode or bytes to either binary or text mode streams '
     stream = kw.get('file', sys.stdout)
+    if stream is None:
+        return
     sep, end = kw.get('sep'), kw.get('end')
     if sep is None:
         sep = ' '