diff --git a/src/Api.js b/src/Api.js
index d439089..90521bc 100644
--- a/src/Api.js
+++ b/src/Api.js
@@ -125,7 +125,7 @@ _postal = {
             tpc = arguments[ 1 ];
         if ( arguments.length === 1 ) {
             channel = arguments[ 0 ].channel || this.configuration.DEFAULT_CHANNEL;
-            tpc = arguments[ 0 ].topic;
+            tpc = arguments[ 0 ].topic || arguments[ 0 ];
         }
         if ( this.subscriptions[ channel ] &&
             Object.prototype.hasOwnProperty.call( this.subscriptions[ channel ], tpc ) ) {