diff --git a/src/Tween.js b/src/Tween.js
index cc270f2b..fe68ac5a 100644
--- a/src/Tween.js
+++ b/src/Tween.js
@@ -271,23 +271,23 @@ TWEEN.Tween.prototype = {
 
 	},
 
-	yoyo: function (yy) {
+	yoyo: function (yoyo) {
 
-		this._yoyo = yy;
+		this._yoyo = yoyo;
 		return this;
 
 	},
 
-	easing: function (eas) {
+	easing: function (easingFunction) {
 
-		this._easingFunction = eas;
+		this._easingFunction = easingFunction;
 		return this;
 
 	},
 
-	interpolation: function (inter) {
+	interpolation: function (interpolationFunction) {
 
-		this._interpolationFunction = inter;
+		this._interpolationFunction = interpolationFunction;
 		return this;
 
 	},