diff --git a/pisi/api.py b/pisi/api.py
index 77ea7d1a..df6eb0b3 100644
--- a/pisi/api.py
+++ b/pisi/api.py
@@ -288,6 +288,10 @@ def configure_pending():
                     pisi.util.join_path(pkg_path, ctx.const.comar_dir),
                     pisi.util.join_path(pkg_path, ctx.const.metadata_xml),
                     pisi.util.join_path(pkg_path, ctx.const.files_xml),
+                    None,
+                    None,
+                    m.package.version,
+                    m.package.release
                 )
                 ctx.ui.notify(pisi.ui.configured, package = pkginfo, files = None)
             ctx.installdb.clear_pending(x)
diff --git a/pisi/atomicoperations.py b/pisi/atomicoperations.py
index 441e6d6a..0d93265a 100644
--- a/pisi/atomicoperations.py
+++ b/pisi/atomicoperations.py
@@ -260,6 +260,13 @@ class Install(AtomicOperation):
         if ctx.comar:
             import pisi.comariface
             try:
+                if self.upgrade:
+                    (iversion, irelease, ibuild) = ctx.installdb.get_version(self.pkginfo.name)
+                    fromVersion = iversion
+                    fromRelease = irelease
+                else:
+                    fromVersion = None
+                    fromRelease = None
                 ctx.ui.notify(pisi.ui.configuring, package = self.pkginfo, files = self.files)
                 pisi.comariface.post_install(
                     self.pkginfo.name,
@@ -267,6 +274,10 @@ class Install(AtomicOperation):
                     self.package.comar_dir(),
                     os.path.join(self.package.pkg_dir(), ctx.const.metadata_xml),
                     os.path.join(self.package.pkg_dir(), ctx.const.files_xml),
+                    fromVersion,
+                    fromRelease,
+                    self.metadata.package.version,
+                    self.metadata.package.release
                     )
                 ctx.ui.notify(pisi.ui.configured, package = self.pkginfo, files = self.files)
             except pisi.comariface.Error:
diff --git a/pisi/comariface.py b/pisi/comariface.py
index 1f53d2e8..09efd28a 100644
--- a/pisi/comariface.py
+++ b/pisi/comariface.py
@@ -93,7 +93,7 @@ def wait_for_result(com, package_name=None):
         elif cmd == com.DENIED:
             raise Error, _("comar denied our access")
 
-def post_install(package_name, provided_scripts, scriptpath, metapath, filepath):
+def post_install(package_name, provided_scripts, scriptpath, metapath, filepath, fromVersion, fromRelease, toVersion, toRelease):
     """Do package's post install operations"""
     
     ctx.ui.info(_("Configuring %s package") % package_name)
@@ -112,8 +112,14 @@ def post_install(package_name, provided_scripts, scriptpath, metapath, filepath)
     wait_for_result(com)
     
     if self_post:
+        args = {
+            "fromVersion": fromVersion,
+            "fromRelease": fromRelease,
+            "toVersion": toVersion,
+            "toRelease": toRelease,
+        }
         ctx.ui.debug(_("Running package's post install script"))
-        com.call_package("System.Package.postInstall", package_name)
+        com.call_package("System.Package.postInstall", package_name, args)
         wait_for_result(com, package_name)
 
 def pre_remove(package_name, metapath, filepath):