diff --git a/bin/Packager/PackagerFactory.py b/bin/Packager/PackagerFactory.py
index dd8e9170f..e59ba832b 100644
--- a/bin/Packager/PackagerFactory.py
+++ b/bin/Packager/PackagerFactory.py
@@ -1,49 +1,49 @@
 #
 # copyright (c) 2009 Ralf Habacker <ralf.habacker@freenet.de>
 #
 
 from Packager.KDEWinPackager import *
 from Packager.CPackPackager import *
 from Packager.SevenZipPackager import *
 from Packager.MSInstallerPackager import *
 from Packager.InnoSetupPackager import *
 
 def init(packager, parent):
     packager.subinfo = parent.subinfo
     packager.parent = parent
     packager.category = parent.category
     packager.package = parent.package
     packager.version = parent.version
     packager.buildTarget = parent.subinfo.buildTarget
     packager.PV = parent.PV
     return
 
 def PackagerFactory(parent, packagerType):
     """provides multi packager type api
     return PackagerBase derived instance for recent settings"""
     utils.debug( "PackagerFactory called", 2 )
     packagers = []
 
     if packagerType:
         for packagerClass in packagerType:
-            if not isinstance(packagerClass, PackagerBase):
+            if not issubclass(packagerClass, PackagerBase):
                 utils.die("PackagerFactory: unsupported packager %s" % packagerClass)
             else:
                 packager = packagerClass()
                 init(packager, parent)
                 packagers.append(packager)
     else:
         # automatic detection
         packager = InnoSetupPackager()
         init(packager, parent)
 
         if packager.configFile() != None:
             packagers.append(packager)
 
         # default packager
         if len(packagers) == 0:
             packager = KDEWinPackager()
             init(packager, parent)
             packagers.append(packager)
     return packagers