1 files changed, 1 insertions, 1 deletions
diff --git a/lib/render-msg.js b/lib/render-msg.js
index 88224f0..5cd6e2d 100644
--- a/lib/render-msg.js
+++ b/lib/render-msg.js
@@ -492,7 +492,7 @@ RenderMsg.prototype.about = function (cb) {
 
   var extras
   for (var k in this.c) {
-    if (!knownAboutProps[k]) {
+    if (this.c[k] !== null && this.c[k] !== '' && !knownAboutProps[k]) {
       if (!extras) extras = {}
       extras[k] = this.c[k]
     }