diff --git a/library/Director/Web/Form/DirectorObjectForm.php b/library/Director/Web/Form/DirectorObjectForm.php
index 1e3df209..a2552ccc 100644
--- a/library/Director/Web/Form/DirectorObjectForm.php
+++ b/library/Director/Web/Form/DirectorObjectForm.php
@@ -183,10 +183,18 @@ abstract class DirectorObjectForm extends QuickForm
             unset($props['vars']);
         }
 
+        $null = array();
         foreach ($props as $k => $v) {
             if (is_bool($v)) {
                 $props[$k] = $v ? 'y' : 'n';
             }
+            if ($v === null) {
+                $null[] = $k;
+            }
+        }
+
+        foreach ($null as $k) {
+            unset($props[$k]);
         }
 
         $this->setDefaults($props);