gistfile1.diff

diff --git a/lib/stack.js b/lib/stack.js
index fc84572..9f6738a 100644
--- a/lib/stack.js
+++ b/lib/stack.js
@@ -346,7 +346,7 @@ Stack.prototype.getSummary = function(callback) {
   var self = this, getter;
 
   if (this.module.get_latestRevision) {
-    getter = this.module.get_latestRevision.bind(null, {environment: this.config.env});
+    getter = this.module.get_latestRevision.bind(this, {environment: this.config.env});
   } else  {
     getter = git.getLatestRevision.bind(git, this.getRepoUrl(), this.stackConfig.tip);
   }