diff --git a/sphinx/quickstart.py b/sphinx/quickstart.py
index b570f5710..e480923d5 100644
--- a/sphinx/quickstart.py
+++ b/sphinx/quickstart.py
@@ -19,7 +19,7 @@ TERM_ENCODING = getattr(sys.stdin, 'encoding', None)
 #try to import readline, unix specific enhancement
 try:
     import readline
-    if 'libedit' in readline.__doc__:
+    if readline.__doc__ and 'libedit' in readline.__doc__:
         readline.parse_and_bind("bind ^I rl_complete")
     else:
         readline.parse_and_bind("tab: complete")