diff --git a/build.py b/build.py
index a3092d63..187b635d 100644
--- a/build.py
+++ b/build.py
@@ -44,7 +44,7 @@ def main():
     if ui == 'cocoa':
         if not dev:
             print "Building help index"
-            os.system('open /Developer/Applications/Utilities/Help\\ Indexer.app --args {0}'.format(help_destpath))
+            os.system('open -a /Developer/Applications/Utilities/Help\\ Indexer.app {0}'.format(help_destpath))
         
         print "Building dg_cocoa.plugin"
         if op.exists('build'):