diff --git a/pisi/api.py b/pisi/api.py
index 350aef2b..4b0d277b 100644
--- a/pisi/api.py
+++ b/pisi/api.py
@@ -293,7 +293,8 @@ def check(package):
                 ctx.ui.info("OK", False)
     return corrupt
 
-def index(dirs, output = 'pisi-index.xml', skip_sources=False):
+def index(dirs=None, output = 'pisi-index.xml', skip_sources=False):
+    """accumulate PISI XML files in a directory"""
     index = Index()
     if not dirs:
         dirs = ['.']
diff --git a/pisi/cli/commands.py b/pisi/cli/commands.py
index af545b4d..83f056b3 100644
--- a/pisi/cli/commands.py
+++ b/pisi/cli/commands.py
@@ -732,10 +732,10 @@ source and binary packages.
         self.init()
         from pisi.api import index
         if len(self.args)>0:
-            index(self.args, ctx.get_option('output'))
+            index(self.args, ctx.get_option('output'), skip_sources = ctx.get_option('skip_sources'))
         elif len(self.args)==0:
             ctx.ui.info(_('Indexing current directory.'))
-            index('.', ctx.get_option('output'), skip_sources = ctx.get_option('skip_sources'))
+            index(['.'], ctx.get_option('output'), skip_sources = ctx.get_option('skip_sources'))
         self.finalize()