diff -r 9aafaf3797e6 -r 75bdaf9fcb25 jitcraft/FixedArray.h
--- a/jitcraft/FixedArray.h	Tue Jul 03 00:43:29 2012 -0700
+++ b/jitcraft/FixedArray.h	Tue Jul 03 00:45:23 2012 -0700
@@ -52,7 +52,7 @@
     }
 
     static inline FixedArray *cast(Object *obj) {
-        assert(obj->is(MapKind_FixedArray));
+        assert(!obj || obj->is(MapKind_FixedArray));
         return reinterpret_cast<FixedArray *>(obj);
     }
 };
@@ -82,7 +82,7 @@
     }
 
     static inline ByteArray *cast(Object *obj) {
-        assert(obj->is(MapKind_ByteArray));
+        assert(!obj || obj->is(MapKind_ByteArray));
         return reinterpret_cast<ByteArray *>(obj);
     }
 };