diff --git a/plugins/sphinx/index.py b/plugins/sphinx/index.py
index 8f93ab9ae..ef1b16718 100755
--- a/plugins/sphinx/index.py
+++ b/plugins/sphinx/index.py
@@ -304,7 +304,7 @@ def sphinxConfParse():
         cmd_index = []
         cmd_delta = []
         for x in range(indexlen):
-            if string.find(sindex[x], ':') != -1:
+            if sindex[x].find(':') != -1:
                 cmd_delta.append(sindex[x])
             else:
                 cmd_index.append(sindex[x])