diff --git a/web/includes/Monitor.php b/web/includes/Monitor.php
index 0d100b58e..d9c6df4c1 100644
--- a/web/includes/Monitor.php
+++ b/web/includes/Monitor.php
@@ -205,8 +205,8 @@ class Monitor extends ZM_Object {
     if ( ZM_RAND_STREAM ) {
       $args['rand'] = time();
     }
-    foreach ( array('scale','height','width') as $int_arg )  {
-      if ( isset($args[$int_arg]) and (!is_int($args[$int_arg]) or !$args[$int_arg] ) ) {
+    foreach ( array('scale') as $int_arg )  {
+      if ( isset($args[$int_arg]) and (!is_numeric($args[$int_arg]) or !$args[$int_arg] ) ) {
         unset($args[$int_arg]);
       }
     }