diff --git a/lib/cli.py b/lib/cli.py
index 8e577409f096b3c70288185db26ddeb49c73093d..e2e1e313fe70e0aebc27341054295a527e90556c 100644
--- a/lib/cli.py
+++ b/lib/cli.py
@@ -947,10 +947,11 @@ MAC_PREFIX_OPT = cli_option("-m", "--mac-prefix", dest="mac_prefix",
 
 MASTER_NETDEV_OPT = cli_option("--master-netdev", dest="master_netdev",
                                help="Specify the node interface (cluster-wide)"
-                               " on which the master IP address will be added "
-                               " [%s]" % constants.DEFAULT_BRIDGE,
+                               " on which the master IP address will be added"
+                               " (cluster init default: %s)" %
+                               constants.DEFAULT_BRIDGE,
                                metavar="NETDEV",
-                               default=constants.DEFAULT_BRIDGE)
+                               default=None)
 
 GLOBAL_FILEDIR_OPT = cli_option("--file-storage-dir", dest="file_storage_dir",
                                 help="Specify the default directory (cluster-"
diff --git a/lib/client/gnt_cluster.py b/lib/client/gnt_cluster.py
index 7476a00fb6c48af37edb895f765740d5b5c6f089..91dafaba79dfe18d8b1431a2e1a8949e57daf969 100644
--- a/lib/client/gnt_cluster.py
+++ b/lib/client/gnt_cluster.py
@@ -70,6 +70,10 @@ def InitCluster(opts, args):
   if opts.drbd_storage and not opts.drbd_helper:
     drbd_helper = constants.DEFAULT_DRBD_HELPER
 
+  master_netdev = opts.master_netdev
+  if master_netdev is None:
+    master_netdev = constants.DEFAULT_BRIDGE
+
   hvlist = opts.enabled_hypervisors
   if hvlist is None:
     hvlist = constants.DEFAULT_ENABLED_HYPERVISOR
@@ -124,7 +128,7 @@ def InitCluster(opts, args):
                         secondary_ip=opts.secondary_ip,
                         vg_name=vg_name,
                         mac_prefix=opts.mac_prefix,
-                        master_netdev=opts.master_netdev,
+                        master_netdev=master_netdev,
                         file_storage_dir=opts.file_storage_dir,
                         enabled_hypervisors=hvlist,
                         hvparams=hvparams,