diff --git a/.travis.yml b/.travis.yml
index e0a9086..1bbff0b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -24,6 +24,7 @@ script:
   - bundle exec rake compile
   - bundle exec rspec spec/c
   - bundle exec rspec spec/v8/context_spec.rb
+  - bundle exec rspec spec/mem
 sudo: false
 addons:
   apt:
diff --git a/ext/v8/isolate.cc b/ext/v8/isolate.cc
index e9e001b..a185128 100644
--- a/ext/v8/isolate.cc
+++ b/ext/v8/isolate.cc
@@ -11,7 +11,7 @@ namespace rr {
     ClassBuilder("Isolate").
       defineSingletonMethod("New", &New).
 
-      defineMethod("Dispose", &Isolate::Dispose).
+      defineMethod("IdleNotificationDeadline", &IdleNotificationDeadline).
 
       store(&Class);
   }
@@ -26,7 +26,6 @@ namespace rr {
     create_params.array_buffer_allocator = &data->array_buffer_allocator;
     v8::Isolate* isolate = v8::Isolate::New(create_params);
 
-
     isolate->SetData(0, data);
     isolate->AddGCPrologueCallback(&clearReferences);
 
@@ -34,9 +33,10 @@ namespace rr {
     return Isolate(isolate);
   }
 
-  VALUE Isolate::Dispose(VALUE self) {
+
+  VALUE Isolate::IdleNotificationDeadline(VALUE self, VALUE deadline_in_seconds) {
     Isolate isolate(self);
-    isolate->Dispose();
-    return Qnil;
+    Locker lock(isolate);
+    return Bool(isolate->IdleNotificationDeadline(NUM2DBL(deadline_in_seconds)));
   }
 }
diff --git a/ext/v8/isolate.h b/ext/v8/isolate.h
index 7fc1480..59d2782 100644
--- a/ext/v8/isolate.h
+++ b/ext/v8/isolate.h
@@ -50,6 +50,7 @@ namespace rr {
      */
     static void destroy(IsolateData* data) {
       Isolate isolate(data);
+      isolate->Dispose();
       isolate.decrementTotalReferences();
     }
 
@@ -159,7 +160,15 @@ namespace rr {
       while (data->rb_release_queue.try_dequeue(object)) {
         isolate.releaseObject(object);
       }
-      rb_gc_mark(data->retained_objects);
+      //TODO: This should not be necessary since sometimes the
+      //instance of V8::RetainedObjects appears to magically be of
+      //type T_NONE instead of T_OBJECT. Later, it will be T_OBJECT,
+      //but if called while T_NONE, it will cause rb_gc_mark to dump
+      //core.
+      //See https://bugs.ruby-lang.org/issues/10803
+      if (TYPE(data->retained_objects) != T_NONE) {
+        rb_gc_mark(data->retained_objects);
+      }
     }
 
     /**
@@ -177,7 +186,7 @@ namespace rr {
     }
 
 
-    static VALUE Dispose(VALUE self);
+    static VALUE IdleNotificationDeadline(VALUE self, VALUE deadline_in_seconds);
 
     /**
      * Recent versions of V8 will segfault unless you pass in an
diff --git a/spec/c/isolate_spec.rb b/spec/c/isolate_spec.rb
index 593c1b7..61656dc 100644
--- a/spec/c/isolate_spec.rb
+++ b/spec/c/isolate_spec.rb
@@ -6,8 +6,4 @@ describe V8::C::Isolate do
   it 'can create a new isolate' do
     expect(isolate).to be
   end
-
-  it "can be disposed of" do
-    isolate.Dispose()
-  end
 end
diff --git a/spec/c_spec_helper.rb b/spec/c_spec_helper.rb
index c57f12c..c0116ad 100644
--- a/spec/c_spec_helper.rb
+++ b/spec/c_spec_helper.rb
@@ -23,8 +23,6 @@ module V8ContextHelpers
         @ctx.Exit
       end
     end
-  ensure
-    @isolate.Dispose()
   end
 end
 
diff --git a/spec/mem/blunt_spec.rb b/spec/mem/blunt_spec.rb
index 7c5a058..a3f346e 100644
--- a/spec/mem/blunt_spec.rb
+++ b/spec/mem/blunt_spec.rb
@@ -7,7 +7,7 @@ describe "A Very blunt test to make sure that we aren't doing stupid leaks", :me
     end
     #allocate a single context to make sure that v8 loads its snapshot and
     #we pay the overhead.
-    V8::Context.new
+    V8::Isolate.new
     @start_memory = process_memory
     GC.stress = true
   end
@@ -15,23 +15,27 @@ describe "A Very blunt test to make sure that we aren't doing stupid leaks", :me
   after do
     GC.stress = false
   end
+
+  it "can create 3 isolates in a row" do
+    3.times { V8::Isolate.new }
+  end
+
   it "won't increase process memory by more than 50% no matter how many contexts we create" do
-    500.times do
-       V8::Context.new
-       run_v8_gc
+    250.times do
+      isolate = V8::Context.new.isolate.native
+      isolate.IdleNotificationDeadline(0.1)
     end
-    process_memory.should <= @start_memory * 1.5
+    expect(process_memory).to be <= @start_memory * 1.5
   end
 
   it "can eval simple value passing statements repeatedly without significantly increasing memory" do
-    V8::C::Locker() do
-      cxt = V8::Context.new
+    V8::Context.new do |cxt|
       500.times do
         cxt.eval('7 * 6')
-        run_v8_gc
+        cxt.isolate.native.IdleNotificationDeadline(0.1)
       end
     end
-      process_memory.should <= @start_memory * 1.1
+    expect(process_memory).to be <= @start_memory * 1.1
   end
 
   def process_memory
@@ -39,4 +43,3 @@ describe "A Very blunt test to make sure that we aren't doing stupid leaks", :me
   end
 
 end
-
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 41785c8..b31ecb4 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,11 +1,5 @@
 require 'v8'
 
-def run_v8_gc
-  V8::C::V8::LowMemoryNotification()
-  while !V8::C::V8::IdleNotification() do
-  end
-end
-
 def rputs(msg)
   puts "<pre>#{ERB::Util.h(msg)}</pre>"
   $stdout.flush