diff --git a/MD_STD.php b/MD_STD.php
index 9ed4f00..f49055c 100644
--- a/MD_STD.php
+++ b/MD_STD.php
@@ -284,6 +284,25 @@ class MD_STD {
 
     }
 
+    /**
+     * Type-safe wrapper around filesize, if output is false, throws an error.
+     *
+     * @param string $filename File name.
+     *
+     * @return integer
+     */
+    public static function filesize(string $filename):int {
+
+        $output = filesize($filename);
+
+        if ($output === false) {
+            throw new Exception("Cannot get filesize of file {$filename}");
+        }
+
+        return $output;
+
+    }
+
     /**
      * Function human_filesize translates byte-level filesizes to human readable ones.
      * Thanks to Jeffrey Sambells http://jeffreysambells.com/2012/10/25/human-readable-filesize-php