diff --git a/Promise.js b/Promise.js
index 5ea53e5..d9ca0d2 100644
--- a/Promise.js
+++ b/Promise.js
@@ -1388,6 +1388,7 @@ object.Mixin('PromiseMixin', 'soft', {
 			// XXX should we just check for .then(..) ???
 			// XXX update README if this changes...
 			: (data.length == 1 
+					&& data[0]
 					&& data[0][Symbol.asyncIterator]
 					&& data[0].then) ?
 				data[0].then(func, ...error)
diff --git a/package.json b/package.json
index dfca9ea..3a58dbd 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ig-types",
-  "version": "6.25.3",
+  "version": "6.25.4",
   "description": "Generic JavaScript types and type extensions...",
   "main": "main.js",
   "scripts": {