diff --git a/src/pylorax/cmdline.py b/src/pylorax/cmdline.py
index 75c6efdb..69b6ccb9 100644
--- a/src/pylorax/cmdline.py
+++ b/src/pylorax/cmdline.py
@@ -105,6 +105,8 @@ def lorax_parser():
                           metavar="[repo]", help="Names of repos to enable")
     optional.add_argument("--disablerepo", action="append", default=[], dest="disablerepos",
                           metavar="[repo]", help="Names of repos to disable")
+    optional.add_argument("--rootfs-size", type=int, default=2,
+                          help="Size of root filesystem in GiB. Defaults to 2.")
 
     # add the show version option
     parser.add_argument("-V", help="show program's version number and exit",
diff --git a/src/sbin/lorax b/src/sbin/lorax
index eabe9702..df4994d3 100755
--- a/src/sbin/lorax
+++ b/src/sbin/lorax
@@ -125,6 +125,7 @@ def main():
               workdir=tempdir, outputdir=opts.outputdir, buildarch=opts.buildarch,
               volid=opts.volid, domacboot=opts.domacboot, doupgrade=opts.doupgrade,
               installpkgs=opts.installpkgs,
+              size=opts.rootfs_size,
               add_templates=opts.add_templates,
               add_template_vars=parsed_add_template_vars,
               add_arch_templates=opts.add_arch_templates,