diff --git a/src/pylorax/__init__.py b/src/pylorax/__init__.py
index 9d2d2299..6db32dda 100644
--- a/src/pylorax/__init__.py
+++ b/src/pylorax/__init__.py
@@ -125,7 +125,7 @@ class Lorax(BaseLoraxClass):
         logger.addHandler(fh)
 
     def run(self, ybo, product, version, release, variant="", bugurl="",
-            isfinal=False, workdir=None, outputdir=None):
+            isfinal=False, workdir=None, outputdir=None, buildarch=None):
 
         assert self._configured
 
@@ -163,8 +163,11 @@ class Lorax(BaseLoraxClass):
         self.inroot = ybo.conf.installroot
         logger.debug("using install root: {0}".format(self.inroot))
 
+        if not buildarch:
+            buildarch = get_buildarch(ybo)
+
         logger.info("setting up build architecture")
-        self.arch = ArchData(get_buildarch(ybo))
+        self.arch = ArchData(buildarch)
         for attr in ('buildarch', 'basearch', 'libdir'):
             logger.debug("self.arch.%s = %s", attr, getattr(self.arch,attr))
 
@@ -252,8 +255,7 @@ def get_buildarch(ybo):
             buildarch = anaconda.arch
             break
     if not buildarch:
-        # fallback to the system architecture
-        logger.warning("using system architecture")
-        buildarch = os.uname()[4]
+        logger.critical("no anaconda package in the repository")
+        sys.exit(1)
 
     return buildarch
diff --git a/src/sbin/lorax b/src/sbin/lorax
index be7160c5..7dc3bf77 100755
--- a/src/sbin/lorax
+++ b/src/sbin/lorax
@@ -70,6 +70,8 @@ def main(args):
     optional.add_option("-e", "--excludepkgs", default=[],
             action="append", metavar="STRING",
             help="package glob to exclude (may be listed multiple times)")
+    optional.add_option("--buildarch", default=None,
+            help="build architecture", metavar="STRING")
 
     # add the option groups to the parser
     parser.add_option_group(required)
@@ -121,7 +123,7 @@ def main(args):
     lorax.configure(conf_file=opts.config)
     lorax.run(yb, opts.product, opts.version, opts.release,
               opts.variant, opts.bugurl, opts.is_beta,
-              workdir=tempdir, outputdir=outputdir)
+              workdir=tempdir, outputdir=outputdir, buildarch=opts.buildarch)
 
 
 def get_yum_base_object(installroot, repositories, mirrorlists=[],