diff --git a/lib/pycall/pytypeobject_wrapper.rb b/lib/pycall/pytypeobject_wrapper.rb
index cb88a082..3518930c 100644
--- a/lib/pycall/pytypeobject_wrapper.rb
+++ b/lib/pycall/pytypeobject_wrapper.rb
@@ -20,12 +20,14 @@ def inherited(subclass)
       subclass.instance_variable_set(:@__pyptr__, __pyptr__)
     end
 
-    def new(*args)
-      wrap_pyptr(LibPython::Helpers.call_object(__pyptr__, *args))
+    def new(*args, &b)
+      wrap_pyptr(LibPython::Helpers.call_object(__pyptr__, *args)).tap do |obj|
+        obj.instance_eval { initialize(&b) }
+      end
     end
 
     def wrap_pyptr(pyptr)
-      return pyptr if pyptr.kind_of? self
+      return pyptr if pyptr.class <= self
       pyptr = pyptr.__pyptr__ if pyptr.kind_of? PyObjectWrapper
       unless pyptr.kind_of? PyPtr
         raise TypeError, "unexpected argument type #{pyptr.class} (expected PyCall::PyPtr)"
diff --git a/spec/pycall/subclass_spec.rb b/spec/pycall/subclass_spec.rb
index e9973853..e91f56e4 100644
--- a/spec/pycall/subclass_spec.rb
+++ b/spec/pycall/subclass_spec.rb
@@ -13,6 +13,10 @@
     Class.new(superclass_wrapper)
   end
 
+  it 'is an instance of subclass' do
+    expect(subclass.new.class).to eq(subclass)
+  end
+
   it 'calls __init__ of superclass' do
     a = subclass.new(1, 2, 3)
     expect(a.init_args.to_a).to eq([1, 2, 3])