diff --git a/runtime/vm/clustered_snapshot.cc b/runtime/vm/clustered_snapshot.cc
index c8d139ce7c9..d57951938a1 100644
--- a/runtime/vm/clustered_snapshot.cc
+++ b/runtime/vm/clustered_snapshot.cc
@@ -4719,6 +4719,7 @@ void Serializer::Serialize() {
   }
 #endif
 
+  Write<int32_t>(num_base_objects_);
   Write<int32_t>(num_objects);
   Write<int32_t>(num_clusters);
 
@@ -5093,6 +5094,7 @@ RawApiError* Deserializer::VerifyVersionAndFeatures(Isolate* isolate) {
 
 
 void Deserializer::Prepare() {
+  num_base_objects_ = Read<int32_t>();
   num_objects_ = Read<int32_t>();
   num_clusters_ = Read<int32_t>();
 
@@ -5102,7 +5104,11 @@ void Deserializer::Prepare() {
 
 
 void Deserializer::Deserialize() {
-  // TODO(rmacnak): Verify num of base objects.
+  if (num_base_objects_ != (next_ref_index_ - 1)) {
+    FATAL2("Snapshot expects %" Pd
+           " base objects, but deserializer provided %" Pd,
+           num_base_objects_, next_ref_index_ - 1);
+  }
 
   {
     NOT_IN_PRODUCT(TimelineDurationScope tds(
@@ -5360,7 +5366,12 @@ FullSnapshotWriter::FullSnapshotWriter(Snapshot::Kind kind,
   // Can't have any mutation happening while we're serializing.
   ASSERT(isolate()->background_compiler() == NULL);
 
-  if (vm_snapshot_data_buffer != NULL) {
+  // TODO(rmacnak): The special case for AOT causes us to always generate the
+  // same VM isolate snapshot for every app. AOT snapshots should be cleaned up
+  // so the VM isolate snapshot is generated separately and each app is
+  // generated from a VM that has loaded this snapshots, much like app-jit
+  // snapshots.
+  if ((vm_snapshot_data_buffer != NULL) && (kind != Snapshot::kAppAOT)) {
     NOT_IN_PRODUCT(TimelineDurationScope tds(
         thread(), Timeline::GetIsolateStream(), "PrepareNewVMIsolate"));
 
@@ -5390,6 +5401,8 @@ FullSnapshotWriter::FullSnapshotWriter(Snapshot::Kind kind,
     Symbols::SetupSymbolTable(isolate());
   } else {
     // Reuse the current vm isolate.
+    saved_symbol_table_ = object_store->symbol_table();
+    new_vm_symbol_table_ = Dart::vm_isolate()->object_store()->symbol_table();
   }
 }
 
diff --git a/runtime/vm/clustered_snapshot.h b/runtime/vm/clustered_snapshot.h
index 8e76043cea4..a91497f170b 100644
--- a/runtime/vm/clustered_snapshot.h
+++ b/runtime/vm/clustered_snapshot.h
@@ -377,6 +377,7 @@ class Deserializer : public StackResource {
   Snapshot::Kind kind_;
   ReadStream stream_;
   InstructionsReader* instructions_reader_;
+  intptr_t num_base_objects_;
   intptr_t num_objects_;
   intptr_t num_clusters_;
   RawArray* refs_;
diff --git a/runtime/vm/snapshot.cc b/runtime/vm/snapshot.cc
index 82a12448e99..d720d0ef67e 100644
--- a/runtime/vm/snapshot.cc
+++ b/runtime/vm/snapshot.cc
@@ -1439,39 +1439,6 @@ bool SnapshotWriter::HandleVMIsolateObject(RawObject* rawobj) {
 #undef VM_OBJECT_WRITE
 
 
-// An object visitor which will iterate over all the script objects in the heap
-// and either count them or collect them into an array. This is used during
-// full snapshot generation of the VM isolate to write out all script
-// objects and their accompanying token streams.
-class ScriptVisitor : public ObjectVisitor {
- public:
-  explicit ScriptVisitor(Thread* thread)
-      : objHandle_(Object::Handle(thread->zone())), count_(0), scripts_(NULL) {}
-
-  ScriptVisitor(Thread* thread, const Array* scripts)
-      : objHandle_(Object::Handle(thread->zone())),
-        count_(0),
-        scripts_(scripts) {}
-
-  void VisitObject(RawObject* obj) {
-    if (obj->IsScript()) {
-      if (scripts_ != NULL) {
-        objHandle_ = obj;
-        scripts_->SetAt(count_, objHandle_);
-      }
-      count_ += 1;
-    }
-  }
-
-  intptr_t count() const { return count_; }
-
- private:
-  Object& objHandle_;
-  intptr_t count_;
-  const Array* scripts_;
-};
-
-
 ForwardList::ForwardList(Thread* thread, intptr_t first_object_id)
     : thread_(thread),
       first_object_id_(first_object_id),