diff --git a/core/5.0/math.d.ts b/core/5.0/math.d.ts
index fcbfa1f..f52893b 100644
--- a/core/5.0/math.d.ts
+++ b/core/5.0/math.d.ts
@@ -95,6 +95,12 @@ declare namespace math {
      */
     function min(x: number, ...numbers: number[]): number;
 
+    /**
+     * Returns the remainder of the division of x by y that rounds the quotient
+     * towards zero. (integer/float)
+     */
+    function mod(x: number, y: number): number;
+
     /**
      * The value of π.
      */