diff --git a/src/scopes.cc b/src/scopes.cc
index cffbef6..f4bcaa8 100644
--- a/src/scopes.cc
+++ b/src/scopes.cc
@@ -40,12 +40,14 @@
 // ----------------------------------------------------------------------------
 // A Zone allocator for use with LocalsMap.
 
+// TODO(isolates): It is probably worth it to change the Allocator class to
+//                 take a pointer to an isolate.
 class ZoneAllocator: public Allocator {
  public:
   /* nothing to do */
   virtual ~ZoneAllocator()  {}
 
-  virtual void* New(size_t size)  { return Zone::New(static_cast<int>(size)); }
+  virtual void* New(size_t size)  { return ZONE->New(static_cast<int>(size)); }
 
   /* ignored - Zone is freed in one fell swoop */
   virtual void Delete(void* p)  {}
@@ -159,16 +161,19 @@
   // This scope's arguments shadow (if present) is context-allocated if an inner
   // scope accesses this one's parameters.  Allocate the arguments_shadow_
   // variable if necessary.
+  Isolate* isolate = Isolate::Current();
   Variable::Mode mode;
   int arguments_shadow_index =
-      scope_info_->ContextSlotIndex(Heap::arguments_shadow_symbol(), &mode);
+      scope_info_->ContextSlotIndex(
+          isolate->heap()->arguments_shadow_symbol(), &mode);
   if (arguments_shadow_index >= 0) {
     ASSERT(mode == Variable::INTERNAL);
-    arguments_shadow_ = new Variable(this,
-                                     Factory::arguments_shadow_symbol(),
-                                     Variable::INTERNAL,
-                                     true,
-                                     Variable::ARGUMENTS);
+    arguments_shadow_ = new Variable(
+        this,
+        isolate->factory()->arguments_shadow_symbol(),
+        Variable::INTERNAL,
+        true,
+        Variable::ARGUMENTS);
     arguments_shadow_->set_rewrite(
         new Slot(arguments_shadow_, Slot::CONTEXT, arguments_shadow_index));
     arguments_shadow_->set_is_used(true);
@@ -213,7 +218,7 @@
   top->AllocateVariables(info->calling_context());
 
 #ifdef DEBUG
-  if (Bootstrapper::IsActive()
+  if (info->isolate()->bootstrapper()->IsActive()
           ? FLAG_print_builtin_scopes
           : FLAG_print_scopes) {
     info->function()->scope()->Print();
@@ -245,7 +250,7 @@
   // such parameter is 'this' which is passed on the stack when
   // invoking scripts
   Variable* var =
-      variables_.Declare(this, Factory::this_symbol(), Variable::VAR,
+      variables_.Declare(this, FACTORY->this_symbol(), Variable::VAR,
                          false, Variable::THIS);
   var->set_rewrite(new Slot(var, Slot::PARAMETER, -1));
   receiver_ = var;
@@ -254,7 +259,7 @@
     // Declare 'arguments' variable which exists in all functions.
     // Note that it might never be accessed, in which case it won't be
     // allocated during variable allocation.
-    variables_.Declare(this, Factory::arguments_symbol(), Variable::VAR,
+    variables_.Declare(this, FACTORY->arguments_symbol(), Variable::VAR,
                        true, Variable::ARGUMENTS);
   }
 }
@@ -269,7 +274,7 @@
 
   // We should never lookup 'arguments' in this scope
   // as it is implicitly present in any scope.
-  ASSERT(*name != *Factory::arguments_symbol());
+  ASSERT(*name != *FACTORY->arguments_symbol());
 
   // Assert that there is no local slot with the given name.
   ASSERT(scope_info_->StackSlotIndex(*name) < 0);
@@ -868,7 +873,7 @@
 
 bool Scope::HasArgumentsParameter() {
   for (int i = 0; i < params_.length(); i++) {
-    if (params_[i]->name().is_identical_to(Factory::arguments_symbol()))
+    if (params_[i]->name().is_identical_to(FACTORY->arguments_symbol()))
       return true;
   }
   return false;
@@ -887,7 +892,7 @@
 
 void Scope::AllocateParameterLocals() {
   ASSERT(is_function_scope());
-  Variable* arguments = LocalLookup(Factory::arguments_symbol());
+  Variable* arguments = LocalLookup(FACTORY->arguments_symbol());
   ASSERT(arguments != NULL);  // functions have 'arguments' declared implicitly
 
   // Parameters are rewritten to arguments[i] if 'arguments' is used in
@@ -942,7 +947,7 @@
     // variable may be allocated in the heap-allocated context (temporaries
     // are never allocated in the context).
     arguments_shadow_ = new Variable(this,
-                                     Factory::arguments_shadow_symbol(),
+                                     FACTORY->arguments_shadow_symbol(),
                                      Variable::INTERNAL,
                                      true,
                                      Variable::ARGUMENTS);
@@ -1008,7 +1013,7 @@
 void Scope::AllocateNonParameterLocal(Variable* var) {
   ASSERT(var->scope() == this);
   ASSERT(var->rewrite() == NULL ||
-         (!var->IsVariable(Factory::result_symbol())) ||
+         (!var->IsVariable(FACTORY->result_symbol())) ||
          (var->AsSlot() == NULL || var->AsSlot()->type() != Slot::LOCAL));
   if (var->rewrite() == NULL && MustAllocate(var)) {
     if (MustAllocateInContext(var)) {