diff --git a/pbuilder-dist b/pbuilder-dist
index 52aace9..22aa356 100755
--- a/pbuilder-dist
+++ b/pbuilder-dist
@@ -1,7 +1,7 @@
 #! /usr/bin/env python
 # -*- coding: utf-8 -*-
 #
-# Copyright (C) 2007-2008 Siegfried-A. Gevatter <rainct@ubuntu.com>
+# Copyright (C) 2007-2009 Siegfried-A. Gevatter <rainct@ubuntu.com>
 # With some changes by Iain Lane <iain@orangesquash.org.uk>
 # Based upon pbuilder-dist-simple by Jamin Collins and Jordan Mantha.
 #
@@ -189,6 +189,9 @@ class pbuilder_dist:
 			base = '--basetgz "%s-base.tgz"' % prefix
 		elif self.builder == 'cowbuilder':
 			base = '--basepath "%s-base.cow"' % prefix
+		else:
+			print 'Error: Unrecognized builder "%s".' % self.builder
+			sys.exit(1)
 		
 		arguments = [
 			'--%s' % self.operation,