diff --git a/src/math/Vector2.js b/src/math/Vector2.js
index 39c899bcc49054c7b910afe0fe43e75743bd4d08..925b6a0036f7e9f21e243d63bb5b5c37b25dc7a0 100644
--- a/src/math/Vector2.js
+++ b/src/math/Vector2.js
@@ -379,15 +379,9 @@ THREE.Vector2.prototype = {
 
 	},
 
-	setLength: function ( l ) {
+	setLength: function ( length ) {
 
-		var oldLength = this.length();
-
-		if ( oldLength !== 0 && l !== oldLength ) {
-
-			this.multiplyScalar( l / oldLength );
-
-		}
+		this.multiplyScalar( length / this.length() );
 
 		return this;
 
diff --git a/src/math/Vector3.js b/src/math/Vector3.js
index d53f32ed4a40ca8698470d1f571f254a69757673..78b2c7d71902a2f8c8f71d3be917247f7f891409 100644
--- a/src/math/Vector3.js
+++ b/src/math/Vector3.js
@@ -584,15 +584,9 @@ THREE.Vector3.prototype = {
 
 	},
 
-	setLength: function ( l ) {
+	setLength: function ( length ) {
 
-		var oldLength = this.length();
-
-		if ( oldLength !== 0 && l !== oldLength  ) {
-
-			this.multiplyScalar( l / oldLength );
-
-		}
+		this.multiplyScalar( length / this.length() );
 
 		return this;
 
@@ -701,7 +695,7 @@ THREE.Vector3.prototype = {
 
 	angleTo: function ( v ) {
 
-		var theta = this.dot( v ) / ( Math.sqrt( this.lengthSq() * v.lengthSq() ) );
+		var theta = this.dot( v ) / Math.sqrt( this.lengthSq() * v.lengthSq() );
 
 		// clamp, to handle numerical problems
 
diff --git a/src/math/Vector4.js b/src/math/Vector4.js
index ce39b1bd12b24fc1afb28ff43a0549a27b52f3b4..00f9c491c2afb2e7f65349fff8e971fccd9c93b3 100644
--- a/src/math/Vector4.js
+++ b/src/math/Vector4.js
@@ -589,15 +589,9 @@ THREE.Vector4.prototype = {
 
 	},
 
-	setLength: function ( l ) {
+	setLength: function ( length ) {
 
-		var oldLength = this.length();
-
-		if ( oldLength !== 0 && l !== oldLength ) {
-
-			this.multiplyScalar( l / oldLength );
-
-		}
+		this.multiplyScalar( length / this.length() );
 
 		return this;