diff --git a/spec/memory_model/base/actionable_spec.rb b/spec/memory_model/base/actionable_spec.rb
index b0a83f8..d1d9c87 100644
--- a/spec/memory_model/base/actionable_spec.rb
+++ b/spec/memory_model/base/actionable_spec.rb
@@ -1,22 +1,25 @@
 require 'spec_helper'
 
 describe MemoryModel::Base::Actionable do
-  let(:klass) do
-    Class.new MemoryModel::Base do
+  let(:model) do
+    Class.new(MemoryModel::Base) do
       field :foo
     end
   end
   let(:value) { 'bar' }
-  subject(:instance) { klass.new(foo: value) }
+  subject(:instance) { model.new(foo: value) }
+  before(:each) do
+    stub_const('MyModel', model)
+  end
 
   describe '#commit' do
     it 'should save to the collection' do
-      expect { instance.commit }.to change { klass.all }
+      expect { instance.commit }.to change { model.all }
     end
 
     it 'should always be the latest record' do
       instance.commit
-      instance.commit.timestamp.should == klass.find(instance.id).timestamp
+      instance.commit.timestamp.should == model.find(instance.id).timestamp
     end
 
     it 'should have a timestamp' do
@@ -52,6 +55,15 @@
     end
   end
 
+  describe '#destroy' do
+    it 'should run a before callback' do
+      #model.before_destroy do
+      #  puts 'destroying'
+      #end
+      instance.commit
+    end
+  end
+
   describe '#dup' do
     it 'should perform a deep_dup' do
       instance.should_receive(:deep_dup)
diff --git a/spec/memory_model/base/attributable_spec.rb b/spec/memory_model/base/attributable_spec.rb
index 6309b16..fa8824b 100644
--- a/spec/memory_model/base/attributable_spec.rb
+++ b/spec/memory_model/base/attributable_spec.rb
@@ -2,14 +2,14 @@
 
 describe MemoryModel::Base::Attributable do
 
-  let(:klass) do
+  let(:model) do
     Class.new(MemoryModel::Base) do
       field :foo
       field :bar
     end
   end
   let(:instance) do
-    klass.new
+    model.new
   end
 
   describe '#any_field_name' do
@@ -62,7 +62,7 @@
     end
 
     it 'should read not initialized' do
-      klass.allocate.inspect.should match /not initialized/
+      model.allocate.inspect.should match /not initialized/
     end
   end
 
@@ -106,7 +106,7 @@
   end
 
   describe '#reset_attribute_to_default' do
-    let(:klass) do
+    let(:model) do
       Class.new(MemoryModel::Base) do
         field :foo, default: 'bar'
       end
@@ -120,7 +120,7 @@
   end
 
   describe '#clear_attribute' do
-    let(:klass) do
+    let(:model) do
       Class.new(MemoryModel::Base) do
         field :foo
       end
diff --git a/spec/memory_model/base/collectable_spec.rb b/spec/memory_model/base/collectable_spec.rb
index c6813bb..a1f97ba 100644
--- a/spec/memory_model/base/collectable_spec.rb
+++ b/spec/memory_model/base/collectable_spec.rb
@@ -2,17 +2,22 @@
 
 describe MemoryModel::Base::Collectable do
 
-  subject(:klass){ Class.new(MemoryModel::Base) }
+  let(:model) do
+    Class.new(MemoryModel::Base) do
+      field :foo
+      field :bar
+    end
+  end
 
   describe '.collection' do
     it 'should be a collection' do
-      klass.collection.should be_a MemoryModel::Collection
+      model.collection.should be_a MemoryModel::Collection
     end
   end
 
   describe '.inherited' do
     it 'should use its parents collection' do
-      Class.new(klass).collection.should == klass.collection
+      Class.new(model).collection.should == model.collection
     end
   end
 
diff --git a/spec/memory_model/base/comparable_spec.rb b/spec/memory_model/base/comparable_spec.rb
index 779432d..8543759 100644
--- a/spec/memory_model/base/comparable_spec.rb
+++ b/spec/memory_model/base/comparable_spec.rb
@@ -1,13 +1,13 @@
 require 'spec_helper'
 
 describe MemoryModel::Base::Comparable do
-  let(:klass) do
-    Class.new MemoryModel::Base do
+  let(:model) do
+    Class.new(MemoryModel::Base) do
       field :foo
     end
   end
   let(:value) { 'bar' }
-  subject(:instance) { klass.new(foo: value) }
+  subject(:instance) { model.new(foo: value) }
 
   describe '#!=' do
     context 'given a symbolized hash' do
@@ -35,8 +35,8 @@
     end
 
     context 'given an instance of the same class' do
-      let(:valid_instance) { klass.new(foo: value) }
-      let(:invalid_instance) { klass.new(foo: 'baz') }
+      let(:valid_instance) { model.new(foo: value) }
+      let(:invalid_instance) { model.new(foo: 'baz') }
       it 'should be true when given a valid instance' do
         (instance != valid_instance).should be_false
       end
@@ -86,8 +86,8 @@
     end
 
     context 'given an instance of the same class' do
-      let(:valid_instance) { klass.new(foo: value) }
-      let(:invalid_instance) { klass.new(foo: 'baz') }
+      let(:valid_instance) { model.new(foo: value) }
+      let(:invalid_instance) { model.new(foo: 'baz') }
       it 'should be true when given a valid instance' do
         (instance == valid_instance).should be_true
       end
@@ -120,8 +120,8 @@
     end
 
     context 'given an instance of the same class' do
-      let(:valid_instance) { klass.new(foo: value) }
-      let(:invalid_instance) { klass.new(foo: 'baz') }
+      let(:valid_instance) { model.new(foo: value) }
+      let(:invalid_instance) { model.new(foo: 'baz') }
       it 'should be true when given a valid instance' do
         (instance === valid_instance).should be_true
       end
@@ -132,9 +132,9 @@
     end
 
     context 'given an instance of an inherited class' do
-      let(:inherited_klass) { Class.new(klass) }
-      let(:valid_instance) { inherited_klass.new(foo: value) }
-      let(:invalid_instance) { inherited_klass.new(foo: 'baz') }
+      let(:inherited_model) { Class.new(model) }
+      let(:valid_instance) { inherited_model.new(foo: value) }
+      let(:invalid_instance) { inherited_model.new(foo: 'baz') }
       it 'should be true when given a valid instance' do
         (instance === valid_instance).should be_true
       end
diff --git a/spec/memory_model/base/versionable_spec.rb b/spec/memory_model/base/versionable_spec.rb
index e33153d..2a7a957 100644
--- a/spec/memory_model/base/versionable_spec.rb
+++ b/spec/memory_model/base/versionable_spec.rb
@@ -2,26 +2,29 @@
 
 describe MemoryModel::Base::Versionable do
 
-  let(:klass) do
+  let(:model) do
     Class.new(MemoryModel::Base)
   end
-  let(:model) do
-    klass.new
+  let(:instance) do
+    model.new
+  end
+  before(:each) do
+    stub_const('MyModel', model)
   end
 
   describe '#versions' do
     it 'should have a number of versions' do
       10.times.each do |index|
-        model.versions.size.should == index
-        model.commit
+        instance.versions.size.should == index
+        instance.commit
       end
     end
   end
 
   describe '#version' do
     it 'should be the latest version' do
-      3.times.each { model.commit }
-      model.version.should == model.versions.keys.last
+      3.times.each { instance.commit }
+      instance.version.should == instance.versions.keys.last
     end
   end
 
diff --git a/spec/memory_model/collection_spec.rb b/spec/memory_model/collection_spec.rb
index 6cff23d..12fcc75 100644
--- a/spec/memory_model/collection_spec.rb
+++ b/spec/memory_model/collection_spec.rb
@@ -5,6 +5,9 @@
   let(:klass) { MemoryModel::Collection }
   let(:model) { Class.new(MemoryModel::Base) }
   subject(:collection) { model.collection }
+  before(:each) do
+    stub_const('MyModel', model)
+  end
 
   describe '.new' do
     it 'should be empty' do
@@ -77,7 +80,7 @@
     it 'should not return a deleted object' do
       instance = model.new
       instance.commit.delete
-      collection.find(instance.id)
+      expect { collection.find(instance.id) }.to raise_error MemoryModel::RecordNotFoundError
     end
 
     context 'with the deleted option' do
@@ -103,7 +106,7 @@
       it 'should return previous version of a deleted object' do
         instance = model.new
         instance.commit.delete
-        collection.find(instance.id).should be_nil
+        expect { collection.find(instance.id) }.to raise_error MemoryModel::RecordNotFoundError
         collection.find(instance.id, version: 1).should be_present
       end
     end