diff --git a/src/RateAdapter.php b/src/RateAdapter.php
index 6ed0a6f..087c0d9 100644
--- a/src/RateAdapter.php
+++ b/src/RateAdapter.php
@@ -95,6 +95,6 @@ abstract class RateAdapter
 
     protected function sortByCost()
     {
-        uasort($this->rates, create_function('$a, $b', 'return ($a->getCost() > $b->getCost());'));
+        uasort($this->rates, function ($a, $b) { return ($a->getCost() > $b->getCost());});
     }
 }
diff --git a/src/Ship.php b/src/Ship.php
index 0ce4c50..570cc82 100644
--- a/src/Ship.php
+++ b/src/Ship.php
@@ -141,6 +141,6 @@ class Ship
 
     protected function sortByCost(& $rates)
     {
-        uasort($rates, create_function('$a, $b', 'return ($a->getCost() > $b->getCost());'));
+        uasort($rates, function ($a, $b) { return ($a->getCost() > $b->getCost());});
     }
 }