diff --git a/CHANGELOG b/CHANGELOG
index 9c67ac8..86a1cd6 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,4 +1,7 @@
 *SVN*
+
+* Ensure $A creates an empty array when its argument's length is undefined. Closes #10574. [henryju, Tobie Langel]
+
 * Fix incorrect variable declaration in Event.fire. Closes #10329. [rubley]
 
 * Fix the way Selector handles [pseudoclass + combinator] with no space in between. Closes #9696. [kangax, fearphage, Andrew Dupont]
diff --git a/src/array.js b/src/array.js
index 245ad13..5bdabb3 100644
--- a/src/array.js
+++ b/src/array.js
@@ -1,7 +1,7 @@
 function $A(iterable) {
   if (!iterable) return [];
   if (iterable.toArray) return iterable.toArray();
-  var length = iterable.length, results = new Array(length);
+  var length = iterable.length || 0, results = new Array(length);
   while (length--) results[length] = iterable[length];
   return results;
 }
@@ -11,7 +11,7 @@ if (Prototype.Browser.WebKit) {
     if (!iterable) return [];
     if (!(Object.isFunction(iterable) && iterable == '[object NodeList]') &&
         iterable.toArray) return iterable.toArray();
-    var length = iterable.length, results = new Array(length);
+    var length = iterable.length || 0, results = new Array(length);
     while (length--) results[length] = iterable[length];
     return results;
   }
diff --git a/test/unit/array.html b/test/unit/array.html
index 95de657..3be5cff 100644
--- a/test/unit/array.html
+++ b/test/unit/array.html
@@ -32,6 +32,9 @@
   var globalArgsTest = 'nothing to see here';
 
   new Test.Unit.Runner({
+    test$A: function(){ with(this) {
+      assertEnumEqual([], $A({}));
+    }},
     
     testToArrayOnArguments: function(){ with(this) {
       function toArrayOnArguments(){