diff --git a/src/JWadhams/JsonLogic.php b/src/JWadhams/JsonLogic.php
index f0d18a0..ac7068f 100644
--- a/src/JWadhams/JsonLogic.php
+++ b/src/JWadhams/JsonLogic.php
@@ -93,7 +93,7 @@ public static function apply($logic = [], $data = [])
                 return ($a <= $b) and ($b <= $c) ;
             },
             '%' => function ($a, $b) {
-                return $a % $b;
+                return fmod($a, $b);
             },
             '!!' => function ($a) {
                 return static::truthy($a);