diff --git a/lib/rpc_backend b/lib/rpc_backend
index ff22bbf..32c3e17 100644
--- a/lib/rpc_backend
+++ b/lib/rpc_backend
@@ -237,7 +237,7 @@
 function iniset_rpc_backend {
     local package=$1
     local file=$2
-    local section=$3
+    local section=${3:-DEFAULT}
     if is_service_enabled zeromq; then
         iniset $file $section rpc_backend "zmq"
         iniset $file $section rpc_zmq_host `hostname`