diff --git a/src/heap/heap-inl.h b/src/heap/heap-inl.h
index e658224..549ecbc 100644
--- a/src/heap/heap-inl.h
+++ b/src/heap/heap-inl.h
@@ -458,8 +458,6 @@
     case PROPERTY_CELL_SPACE:
     case LO_SPACE:
       return false;
-    case INVALID_SPACE:
-      break;
   }
   UNREACHABLE();
   return false;
@@ -589,7 +587,7 @@
 Isolate* Heap::isolate() {
   return reinterpret_cast<Isolate*>(
       reinterpret_cast<intptr_t>(this) -
-      reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(4)->heap()) + 4);
+      reinterpret_cast<size_t>(reinterpret_cast<Isolate*>(16)->heap()) + 16);
 }
 
 
@@ -699,7 +697,7 @@
 
 
 void Heap::ClearInstanceofCache() {
-  set_instanceof_cache_function(the_hole_value());
+  set_instanceof_cache_function(Smi::FromInt(0));
 }
 
 
@@ -709,8 +707,8 @@
 
 
 void Heap::CompletelyClearInstanceofCache() {
-  set_instanceof_cache_map(the_hole_value());
-  set_instanceof_cache_function(the_hole_value());
+  set_instanceof_cache_map(Smi::FromInt(0));
+  set_instanceof_cache_function(Smi::FromInt(0));
 }