diff --git a/lib/canvas.js b/lib/canvas.js
index 91c1d05..fa11b17 100644
--- a/lib/canvas.js
+++ b/lib/canvas.js
@@ -126,6 +126,14 @@ Canvas.prototype.getContext = function(contextId){
   }
 };
 
+/**
+ * Add `color` stop at the given `offset`.
+ *
+ * @param {Number} offset
+ * @param {String} color
+ * @api public
+ */
+
 CanvasGradient.prototype.addColorStop = function(offset, color){
   var rgba;
   if (rgba = parseColor(color)) {
@@ -138,17 +146,49 @@ CanvasGradient.prototype.addColorStop = function(offset, color){
   }
 };
 
+/**
+ * Create a linear gradient at the given point `(x0, y0)` and `(x1, y1)`.
+ *
+ * @param {Number} x0
+ * @param {Number} y0
+ * @param {Number} x1
+ * @param {Number} y1
+ * @return {CanvasGradient}
+ * @api public
+ */
+
 Context2d.prototype.createLinearGradient = function(x0, y0, x1, y1){
   return new CanvasGradient(x0, y0, x1, y1);
 };
 
+/**
+ * Create a radial gradient at the given point `(x0, y0)` and `(x1, y1)`
+ * and radius `r0` and `r1`.
+ *
+ * @param {Number} x0
+ * @param {Number} y0
+ * @param {Number} r0
+ * @param {Number} x1
+ * @param {Number} y1
+ * @param {Number} r1
+ * @return {CanvasGradient}
+ * @api public
+ */
+
 Context2d.prototype.createRadialGradient = function(x0, y0, r0, x1, y1, r1){
   return new CanvasGradient(x0, y0, r0, x1, y1, r1);
 };
 
+/**
+ * Reset transform matrix to identity, then apply the given args.
+ *
+ * @param {...}
+ * @api public
+ */
+
 Context2d.prototype.setTransform = function(){
   this.resetTransform();
-  return this.transform.apply(this, arguments);
+  this.transform.apply(this, arguments);
 };
 
 /**