diff --git a/lib/random.php b/lib/random.php
index 3b8952f..dedd453 100644
--- a/lib/random.php
+++ b/lib/random.php
@@ -92,10 +92,10 @@
                     PATH_SEPARATOR,
                     strtolower($RandomCompat_basedir)
                 );
-                $RandomCompatUrandom = in_array(
-                    '/dev',
+                $RandomCompatUrandom = (array() !== array_intersect(
+                    array('/dev', '/dev/', '/dev/urandom'),
                     $RandomCompat_open_basedir
-                );
+                ));
                 $RandomCompat_open_basedir = null;
             }