diff --git a/verify.php b/verify.php
index 8869d00..10d3039 100644
--- a/verify.php
+++ b/verify.php
@@ -237,7 +237,7 @@ class verify
     */
   public static function staticIs_integer ($val)
   {
-    if (! is_string ($val) || trim ($val) === "")
+    if (! is_string ($val) || trim ($val) === "" || ! is_int ($val))
       return false;
     if (strspn ($val, "0123456789") !== strlen ($val))
       return false;