diff --git a/index.js b/index.js
index b2ed655..4b81ee0 100644
--- a/index.js
+++ b/index.js
@@ -913,7 +913,7 @@ rrp.decode = function (buf, offset) {
 rrp.decode.bytes = 0
 
 rrp.encodingLength = function (data) {
-  return 2 + name.encodingLength(data.mbox) + name.encodingLength(data.txt || '.')
+  return 2 + name.encodingLength(data.mbox || '.') + name.encodingLength(data.txt || '.')
 }
 
 const typebitmap = {}
diff --git a/test.js b/test.js
index c49bf8f..207d623 100644
--- a/test.js
+++ b/test.js
@@ -405,9 +405,12 @@ tape('rrp', function (t) {
     txt: 'baz.bar.com'
   })
   testEncoder(t, packet.rp, {
-    mbox: 'rp.world.com',
-    txt: '.'
+    mbox: 'foo.bar.com'
   })
+  testEncoder(t, packet.rp, {
+    txt: 'baz.bar.com'
+  })
+  testEncoder(t, packet.rp, {})
   t.end()
 })