diff --git a/src/CanvasRenderingContext2d.cc b/src/CanvasRenderingContext2d.cc
index 15bf7c5..0ef4da5 100644
--- a/src/CanvasRenderingContext2d.cc
+++ b/src/CanvasRenderingContext2d.cc
@@ -386,6 +386,10 @@ Context2d::New(const Arguments &args) {
 
 /*
  * Draw image src image to the destination (context).
+ *
+ * dx, dy
+ * dx, dy, dw, dh
+ * sx, sy, sw, sh, dx, dy, dw, dh
  */
 
 Handle<Value>