diff --git a/Gemfile b/Gemfile
index 7a29947..648b7a1 100644
--- a/Gemfile
+++ b/Gemfile
@@ -4,4 +4,4 @@ gem "hoe"
 gem "hoe-gemspec"
 gem "rspec"
 gem "rake-compiler"
-gem "yard", "0.7.5"
\ No newline at end of file
+gem "yard"
\ No newline at end of file
diff --git a/ext/opencv/cvcontourtree.cpp b/ext/opencv/cvcontourtree.cpp
index 9bb896d..bb8b833 100644
--- a/ext/opencv/cvcontourtree.cpp
+++ b/ext/opencv/cvcontourtree.cpp
@@ -12,6 +12,7 @@
  * Document-class: OpenCV::CvContourTree
  *
  * Contour tree
+ *
  * @see CvContour#create_tree
  */
 __NAMESPACE_BEGIN_OPENCV
@@ -25,26 +26,6 @@ rb_class()
   return rb_klass;
 }
 
-void
-define_ruby_class()
-{
-  if (rb_klass)
-    return;
-  /* 
-   * opencv = rb_define_module("OpenCV");
-   * cvseq = rb_define_class_under(opencv, "CvSeq");
-   *
-   * note: this comment is used by rdoc.
-   */
-  VALUE opencv = rb_module_opencv();
-  VALUE cvseq = cCvSeq::rb_class();
-  
-  rb_klass = rb_define_class_under(opencv, "CvContourTree", cvseq);
-  rb_define_method(rb_klass, "p1", RUBY_METHOD_FUNC(rb_p1), 0);
-  rb_define_method(rb_klass, "p2", RUBY_METHOD_FUNC(rb_p2), 0);
-  rb_define_method(rb_klass, "contour", RUBY_METHOD_FUNC(rb_contour), 1);
-}
-
 /*
  * Returns the first point of the binary tree root segment
  * @overload p1
@@ -92,5 +73,24 @@ rb_contour(VALUE self, VALUE criteria)
   return cCvSeq::new_sequence(cCvContour::rb_class(), contour, cCvPoint::rb_class(), storage);
 }
 
+void
+init_ruby_class()
+{
+#if 0
+  // For documentation using YARD
+  VALUE opencv = rb_define_module("OpenCV");
+  VALUE cvseq = rb_define_class_under(opencv, "CvSeq");
+#endif
+  if (rb_klass)
+    return;
+  VALUE opencv = rb_module_opencv();
+  VALUE cvseq = cCvSeq::rb_class();
+
+  rb_klass = rb_define_class_under(opencv, "CvContourTree", cvseq);
+  rb_define_method(rb_klass, "p1", RUBY_METHOD_FUNC(rb_p1), 0);
+  rb_define_method(rb_klass, "p2", RUBY_METHOD_FUNC(rb_p2), 0);
+  rb_define_method(rb_klass, "contour", RUBY_METHOD_FUNC(rb_contour), 1);
+}
+
 __NAMESPACE_END_CVCONTOURTREE
 __NAMESPACE_END_OPENCV
diff --git a/ext/opencv/cvcontourtree.h b/ext/opencv/cvcontourtree.h
index 685500f..570fcde 100644
--- a/ext/opencv/cvcontourtree.h
+++ b/ext/opencv/cvcontourtree.h
@@ -19,7 +19,7 @@ __NAMESPACE_BEGIN_CVCONTOURTREE
 
 VALUE rb_class();
 
-void define_ruby_class();
+void init_ruby_class();
 
 VALUE rb_p1(VALUE self);
 VALUE rb_p2(VALUE self);
diff --git a/ext/opencv/opencv.cpp b/ext/opencv/opencv.cpp
index 3247a17..fb2a011 100644
--- a/ext/opencv/opencv.cpp
+++ b/ext/opencv/opencv.cpp
@@ -665,7 +665,7 @@ extern "C" {
     mOpenCV::mPointSet::define_ruby_module();
     mOpenCV::cCvChain::define_ruby_class();
     mOpenCV::cCvContour::define_ruby_class();
-    mOpenCV::cCvContourTree::define_ruby_class();
+    mOpenCV::cCvContourTree::init_ruby_class();
 
     mOpenCV::cCvMat::define_ruby_class();
     mOpenCV::cIplImage::define_ruby_class();