diff --git a/lib/vows/suite.js b/lib/vows/suite.js
index 195c56f..014571f 100644
--- a/lib/vows/suite.js
+++ b/lib/vows/suite.js
@@ -228,7 +228,7 @@ this.Suite.prototype = new(function () {
                     // synchronously.
                     if (topic &&
                         ctx.name !== 'on' &&
-                        !topic._vowsEmitedEvents.hasOwnProperty(ctx.event)) {
+                        (!topic._vowsEmitedEvents || !topic._vowsEmitedEvents.hasOwnProperty(ctx.event))) {
                         topic.on(ctx.event, function (ctx) {
                             return function (val) {
                                 return run(new(Context)(vow, ctx, env), lastTopic);