diff --git a/Promise.js b/Promise.js
index db43907..9716923 100644
--- a/Promise.js
+++ b/Promise.js
@@ -260,12 +260,13 @@ object.Constructor('InteractivePromise', Promise, {
 		var handlers = []
 
 		var onmessage = function(func){
-			// remove all handlers... (XXX TEST)
+			// remove all handlers...
 			if(func === false){
-				obj == null ?
-					handlers.splice(0, handlers.length)
-					: (delete obj.__message_handlers)
-			// remove a specific handler... (XXX TEST)
+				var h = (obj == null ?
+					handlers
+					: (obj.__message_handlers || []))
+				h.splice(0, handlers.length)
+			// remove a specific handler...
 			} else if(arguments[1] === false){
 				var h = (obj == null ?
 					handlers
@@ -296,6 +297,8 @@ object.Constructor('InteractivePromise', Promise, {
 		Object.defineProperty(obj, '__message_handlers', {
 			value: handlers,
 			enumerable: false,
+			// XXX should this be .configurable???
+			configurable: true,
 		})
    		return obj },
 })
diff --git a/package.json b/package.json
index a1bbc77..1a4e9ae 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ig-types",
-  "version": "6.0.12",
+  "version": "6.0.13",
   "description": "Generic JavaScript types and type extensions...",
   "main": "main.js",
   "scripts": {