diff --git a/src/sbeam.py b/src/sbeam.py
index 2fc3c08..b23bc30 100755
--- a/src/sbeam.py
+++ b/src/sbeam.py
@@ -44,6 +44,9 @@ def serve(recursive, filename):
     """Start a SuperBeam serve to serve FILENAME [FILENAME ...].
 
     FILENAME can be one or more files or directories.
+
+    :param recursive boolean: recursive directory processing
+    :param filename str: filename or directory to serve
     """
     filelist = SuperBeam.build_filelist(filename, recursive)
     SuperBeam.serve_forever(filelist)