diff -r 3ac2a36a7a0c -r cf82769eb136 src/Parser.cpp
--- a/src/Parser.cpp	Sun Aug 05 14:19:19 2012 -0700
+++ b/src/Parser.cpp	Sun Aug 05 15:38:52 2012 -0700
@@ -1226,16 +1226,21 @@
 }
 
 static inline bool
-DeclareIntrinsicType(Zone *zone, Scope *scope, const char *name, PrimitiveType type)
+DeclareIntrinsicType(Zone *zone, Scope *scope, const char *name, Handle<Type> type)
 {
     Local<String> tag(zone, zone->makeSymbol(name));
     if (!tag)
         return false;
 
+    return !!scope->declareType(tag, type);
+}
+
+static inline bool
+DeclareIntrinsicType(Zone *zone, Scope *scope, const char *name, PrimitiveType type)
+{
     Local<Type> primitive(zone, zone->types()->getPrimitive(type));
     assert(primitive);
-
-    return !!scope->declareType(tag, primitive);
+    return DeclareIntrinsicType(zone, scope, name, primitive);
 }
 
 bool
@@ -1249,6 +1254,11 @@
         return false;
     if (!DeclareIntrinsicType(zone_, scope_, "String", PrimitiveType_Char))
         return false;
+
+    Local<Type> unchecked(zone_, zone_->types()->getUnchecked());
+    if (!DeclareIntrinsicType(zone_, scope_, "unchecked", unchecked))
+        return false;
+
     return true;
 }