diff --git a/osc/conf.py b/osc/conf.py
index cfcfc5c2..edebe4f0 100644
--- a/osc/conf.py
+++ b/osc/conf.py
@@ -90,7 +90,7 @@ DEFAULTS = {'apiurl': 'https://api.opensuse.org',
             # build type settings
             'build-cmd': '/usr/bin/build',
             'build-type': '',                   # may be empty for chroot, kvm or xen
-            'build-root': '/var/tmp/build-root',
+            'build-root': '/var/tmp/build-root/%(repo)s-%s(arch)s',
             'build-uid': '',                    # use the default provided by build
             'build-device': '',                 # required for VM builds
             'build-memory': '',                 # required for VM builds