diff --git a/magnum/drivers/k8s_coreos_v1/templates/fragments/write-kube-os-config.sh b/magnum/drivers/k8s_coreos_v1/templates/fragments/write-kube-os-config.sh
index 27fa71c6a1..8e3cfc66ed 100644
--- a/magnum/drivers/k8s_coreos_v1/templates/fragments/write-kube-os-config.sh
+++ b/magnum/drivers/k8s_coreos_v1/templates/fragments/write-kube-os-config.sh
@@ -5,7 +5,7 @@
 KUBE_OS_CLOUD_CONFIG=/etc/sysconfig/kube_openstack_config
 
 # kubernetes backend only support keystone v2 at this point
-AUTH_URL=$(echo "$AUTH_URL" | tr -s "v3" "v2")
+AUTH_URL=$(echo "$AUTH_URL" | sed 's/v3/v2/')
 
 # Generate a the configuration for Kubernetes services
 # to talk to OpenStack Neutron
diff --git a/magnum/drivers/k8s_fedora_atomic_v1/templates/fragments/write-kube-os-config.sh b/magnum/drivers/k8s_fedora_atomic_v1/templates/fragments/write-kube-os-config.sh
index 27fa71c6a1..8e3cfc66ed 100644
--- a/magnum/drivers/k8s_fedora_atomic_v1/templates/fragments/write-kube-os-config.sh
+++ b/magnum/drivers/k8s_fedora_atomic_v1/templates/fragments/write-kube-os-config.sh
@@ -5,7 +5,7 @@
 KUBE_OS_CLOUD_CONFIG=/etc/sysconfig/kube_openstack_config
 
 # kubernetes backend only support keystone v2 at this point
-AUTH_URL=$(echo "$AUTH_URL" | tr -s "v3" "v2")
+AUTH_URL=$(echo "$AUTH_URL" | sed 's/v3/v2/')
 
 # Generate a the configuration for Kubernetes services
 # to talk to OpenStack Neutron