diff --git a/cachefile.php b/cachefile.php
index dfe347e..cfcd349 100644
--- a/cachefile.php
+++ b/cachefile.php
@@ -195,7 +195,7 @@ class cachefile
     }
 
     $this->garbage ();
-    if (! is_string ($id) || ! is_integer ($id))
+    if (! is_string ($id) && ! is_integer ($id))
       throw new \Exception ("CacheFile read ID not a string : ".gettype ($id),
       500);
     $fileCache = $this->directory."/".sha1 ($id);