diff --git a/plugins/sphinx/index.py b/plugins/sphinx/index.py
index 026f88e16..0ae17d7b4 100755
--- a/plugins/sphinx/index.py
+++ b/plugins/sphinx/index.py
@@ -212,7 +212,7 @@ def rebuild():
     file = initDreplace()
     cmd = file + ' rebuild &'
     data = mw.execShell(cmd)
-    if data[0].find('successfully'):
+    if data[0].find('successfully')<0:
         return data[0].replace("\n","<br/>")
     return 'ok'