diff --git a/Math/Math/Vector.swift b/Math/Math/Vector.swift
index 9fbabf9..069a675 100644
--- a/Math/Math/Vector.swift
+++ b/Math/Math/Vector.swift
@@ -107,18 +107,8 @@ public struct Vector3: Vector {
             data[2] = value
         }
     }
-
-    // MARK: Operators
-
-    public func cross(rhs: Vector3) -> Vector3 {
-        return Vector3(x: data[1] * rhs.data[2] - data[2] * rhs.data[1],
-                       y: data[2] * rhs.data[0] - data[0] * rhs.data[2],
-                       z: data[0] * rhs.data[1] - data[1] * rhs.data[0])
-    }
 }
 
-//------------------------------------------------------------------------------
-
 public struct Vector4: Vector {
     private var data: [Float]
 
@@ -180,6 +170,14 @@ extension Vector {
     }
 }
 
+extension Vector3 {
+    public func cross(rhs: Vector3) -> Vector3 {
+        return Vector3(x: data[1] * rhs.data[2] - data[2] * rhs.data[1],
+            y: data[2] * rhs.data[0] - data[0] * rhs.data[2],
+            z: data[0] * rhs.data[1] - data[1] * rhs.data[0])
+    }
+}
+
 public prefix func -<T: Vector>(v: T) -> T {
     var out = v
     for i in 0..<out.count {