diff --git a/tools/appliance/definitions/systemvm64template/postinstall.sh b/tools/appliance/definitions/systemvm64template/postinstall.sh
index 1a701ae52cb..0b204482c5e 100644
--- a/tools/appliance/definitions/systemvm64template/postinstall.sh
+++ b/tools/appliance/definitions/systemvm64template/postinstall.sh
@@ -49,7 +49,7 @@ install_packages() {
   # nfs client
   apt-get --no-install-recommends -q -y --force-yes install nfs-common
   # nfs irqbalance
-  apt-get --no-install-recommends -q -y --force-yes install irqbalance
+  apt-get --no-install-recommends -q -y --force-yes -t wheezy-backports install irqbalance
 
   # cifs client
   apt-get --no-install-recommends -q -y --force-yes install samba-common
diff --git a/tools/appliance/definitions/systemvmtemplate/postinstall.sh b/tools/appliance/definitions/systemvmtemplate/postinstall.sh
index aa6a1c0eb05..71afed3d56c 100644
--- a/tools/appliance/definitions/systemvmtemplate/postinstall.sh
+++ b/tools/appliance/definitions/systemvmtemplate/postinstall.sh
@@ -49,7 +49,7 @@ install_packages() {
   # nfs client
   apt-get --no-install-recommends -q -y --force-yes install nfs-common
   # nfs irqbalance
-  apt-get --no-install-recommends -q -y --force-yes install irqbalance
+  apt-get --no-install-recommends -q -y --force-yes -t wheezy-backports install irqbalance
 
   # cifs client
   apt-get --no-install-recommends -q -y --force-yes install samba-common