diff --git a/src/calibre/__init__.py b/src/calibre/__init__.py
index 28ae96d32f..e1196ea176 100644
--- a/src/calibre/__init__.py
+++ b/src/calibre/__init__.py
@@ -381,7 +381,7 @@ def strftime(fmt, t=time.localtime()):
 
 def my_unichr(num):
     try:
-        unichr(num)
+        return unichr(num)
     except ValueError:
         return u'?'