diff --git a/mock/default.cfg b/mock/default.cfg
index 7cb7b7b..1667f7c 100644
--- a/mock/default.cfg
+++ b/mock/default.cfg
@@ -12,7 +12,7 @@ config_opts['yum.conf'] = """
 name = epel
 gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-EPEL-7
 enabled = 1
-baseurl = http://www.uk.xensource.com/linux/distros/CentOS/7.1.1503/EPEL-20150814/x86_64/
+baseurl = http://www.uk.xensource.com/linux/distros/CentOS/7.1.1503/EPEL-20150910/x86_64/
 gpgcheck = 1
 exclude=ocaml*
 
@@ -36,7 +36,7 @@ exclude=ocaml*
 name = updates
 gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
 enabled = 1
-baseurl = http://www.uk.xensource.com/linux/distros/CentOS/7.1.1503/updates-20150814/x86_64/
+baseurl = http://www.uk.xensource.com/linux/distros/CentOS/7.1.1503/updates-20150910/x86_64/
 gpgcheck = 1
 exclude=ocaml*
 
@@ -44,7 +44,7 @@ exclude=ocaml*
 name = extras
 gpgkey = file:///etc/pki/rpm-gpg/RPM-GPG-KEY-CentOS-7
 enabled = 1
-baseurl = http://www.uk.xensource.com/linux/distros/CentOS/7.1.1503/extras-20150814/x86_64/
+baseurl = http://www.uk.xensource.com/linux/distros/CentOS/7.1.1503/extras-20150910/x86_64/
 gpgcheck = 1
 exclude=ocaml*