diff -r 7926a7921fa3 -r 0d28dc5af6c7 src/BytecodeCompiler.cpp
--- a/src/BytecodeCompiler.cpp	Sun Aug 05 00:45:06 2012 -0700
+++ b/src/BytecodeCompiler.cpp	Sun Aug 05 00:49:31 2012 -0700
@@ -744,6 +744,13 @@
     if (!map)
         return NULL;
 
+    // Ensure the inner type has an array map if needed.
+    if (type->contained()->isArray()) {
+        Local<Type> contained(zone, type->contained());
+        if (!BuildArrayMap(zone, contained))
+            return NULL;
+    }
+
     type->setNewMap(map);
     return map;
 }