diff --git a/ext/attribute_dictionary.c b/ext/attribute_dictionary.c
index 4c0cfef..b2fb3bf 100644
--- a/ext/attribute_dictionary.c
+++ b/ext/attribute_dictionary.c
@@ -153,5 +153,6 @@ VALUE AttributeDictionary_Init(VALUE Sketchup, VALUE Sketchup_Entity)
 	rb_define_method(Sketchup_AttributeDictionary, "keys", Sketchup_AttributeDictionary_keys, 0);
 	rb_define_method(Sketchup_AttributeDictionary, "values", Sketchup_AttributeDictionary_values, 0);
 	rb_define_method(Sketchup_AttributeDictionary, "delete_key", Sketchup_AttributeDictionary_delete_key, 1);
+	rb_define_alias(Sketchup_AttributeDictionary, "count", "size");
 	return Sketchup_AttributeDictionary;
 }
\ No newline at end of file
diff --git a/test/test_attribute_dictionary.rb b/test/test_attribute_dictionary.rb
index a2dcea3..1f40e53 100644
--- a/test/test_attribute_dictionary.rb
+++ b/test/test_attribute_dictionary.rb
@@ -77,6 +77,10 @@ def test_size
     assert_equal(7, @attribute_dictionary.size)
   end
 
+  def test_count_is_alias_of_size
+    assert_equal(@attribute_dictionary.size, @attribute_dictionary.count)
+  end
+
   def test_values
     assert_equal(
       [0.1557307335588798, 40.018309, 'Manual', -105.242139, -18_871_519.616960514, -174_402_260.58333763, false],