diff --git a/py/cmdline/pylookup.py b/py/cmdline/pylookup.py
index 69f26a6aa..e9e21346a 100755
--- a/py/cmdline/pylookup.py
+++ b/py/cmdline/pylookup.py
@@ -1,7 +1,7 @@
 #!/usr/bin/env python 
 
 """\
-py.lookup SEARCH_STRING [options]
+py.lookup [search_directory] SEARCH_STRING [options]
 
 Looks recursively at Python files for a SEARCH_STRING, starting from the
 present working directory. Prints the line, with the filename and line-number