diff --git a/pisi/index.py b/pisi/index.py
index 0e275412..d6be339c 100644
--- a/pisi/index.py
+++ b/pisi/index.py
@@ -97,6 +97,7 @@ class Index(XmlFile):
 
         md = metadata.MetaData()
         md.read(os.path.join(ctx.config.install_dir(), ctx.const.metadata_xml))
+        md.package.packageSize = os.path.getsize(path)
         if ctx.config.options and ctx.config.options.absolute_uris:
             # FIXME: the name "absolute_uris" does not seem to fit below :/
             md.package.packageURI = os.path.realpath(path)
diff --git a/pisi/metadata.py b/pisi/metadata.py
index 30935855..6ec345f4 100644
--- a/pisi/metadata.py
+++ b/pisi/metadata.py
@@ -47,6 +47,7 @@ class Package(specfile.Package):
     t_DistributionRelease = [ autoxml.String, autoxml.mandatory]
     t_Architecture = [ autoxml.String, autoxml.mandatory]
     t_InstalledSize = [ autoxml.Long, autoxml.mandatory]
+    t_PackageSize = [ autoxml.Long, autoxml.optional]
     t_PackageURI = [ autoxml.String, autoxml.optional]
 
     def decode_hook(self, node, errs, where):