diff --git a/ext/opencv/rect.cpp b/ext/opencv/rect.cpp
index 9cc1686..e07abb9 100644
--- a/ext/opencv/rect.cpp
+++ b/ext/opencv/rect.cpp
@@ -47,12 +47,14 @@ namespace rubyopencv {
     /*
      * Create a rectangle
      *
-     * @overload new(x = 0, y = 0, width = 0, height = 0)
-     * @param x [Integer] x coordinate
-     * @param y [Integer] y coordinate
-     * @param width [Integer] Width
-     * @param height [Integer] Height
-     * @return [Rect] new rectangle
+     * @overload new()
+     *   @return [Rect] new rectangle
+     * @overload new(x, y, width, height)
+     *   @param x [Integer] x coordinate
+     *   @param y [Integer] y coordinate
+     *   @param width [Integer] Width
+     *   @param height [Integer] Height
+     *   @return [Rect] new rectangle
      */
     VALUE rb_initialize(int argc, VALUE *argv, VALUE self) {
       const int SIZE = 4;
@@ -73,6 +75,9 @@ namespace rubyopencv {
 	selfptr->width = NUM2INT(values[2]);
 	selfptr->height = NUM2INT(values[3]);
 	break;
+      default:
+	rb_raise(rb_eArgError, "wrong number of arguments (%d for 0 or 4)", argc);
+	break;
       }
 
       return self;
diff --git a/test/test_rect.rb b/test/test_rect.rb
new file mode 100755
index 0000000..f04e17b
--- /dev/null
+++ b/test/test_rect.rb
@@ -0,0 +1,86 @@
+#!/usr/bin/env ruby
+# -*- mode: ruby; coding: utf-8 -*-
+require 'test/unit'
+require 'opencv'
+require File.expand_path(File.dirname(__FILE__)) + '/helper'
+
+include OpenCV
+
+# Tests for OpenCV::Rect
+class TestRect < OpenCVTestCase
+  def test_x
+    rect = Rect.new
+    rect.x = 100
+    assert_equal(100, rect.x)
+    rect.x = 200
+    assert_equal(200, rect.x)
+  end
+
+  def test_y
+    rect = Rect.new
+    rect.y = 100
+    assert_equal(100, rect.y)
+    rect.y = 200
+    assert_equal(200, rect.y)
+  end
+
+  def test_width
+    rect = Rect.new
+    rect.width = 100
+    assert_equal(100, rect.width)
+    rect.width = 200
+    assert_equal(200, rect.width)
+  end
+
+  def test_height
+    rect = Rect.new
+    rect.height = 100
+    assert_equal(100, rect.height)
+    rect.height = 200
+    assert_equal(200, rect.height)
+  end
+
+  def test_initialize
+    rect = Rect.new
+    assert_equal(0, rect.x)
+    assert_equal(0, rect.y)
+    assert_equal(0, rect.width)
+    assert_equal(0, rect.height)
+
+    rect = Rect.new(10, 20, 30, 40)
+    assert_equal(10, rect.x)
+    assert_equal(20, rect.y)
+    assert_equal(30, rect.width)
+    assert_equal(40, rect.height)
+
+    assert_raise(TypeError) {
+      Rect.new(DUMMY_OBJ, 1, 1, 1)
+    }
+    assert_raise(TypeError) {
+      Rect.new(1, DUMMY_OBJ, 1, 1)
+    }
+    assert_raise(TypeError) {
+      Rect.new(1, 1, DUMMY_OBJ, 1)
+    }
+    assert_raise(TypeError) {
+      Rect.new(1, 1, 1, DUMMY_OBJ)
+    }
+    assert_raise(ArgumentError) {
+      Rect.new(1)
+    }
+    assert_raise(ArgumentError) {
+      Rect.new(1, 2)
+    }
+    assert_raise(ArgumentError) {
+      Rect.new(1, 2, 3)
+    }
+    assert_raise(ArgumentError) {
+      Rect.new(1, 2, 3, 4, 5)
+    }
+  end
+
+  def test_to_s
+    rect = Rect.new(1, 2, 3, 4)
+    assert_equal('#<OpenCV::Rect:[3 x 4 from (1, 2)]>', rect.to_s)
+  end
+end