diff --git a/include/class.forms.php b/include/class.forms.php
index 2ef313db867c739ca67389a8d0e0e97f635b9b87..6e2ddffc84313ffc547ceb0387eff3c9d7c49a75 100644
--- a/include/class.forms.php
+++ b/include/class.forms.php
@@ -1833,7 +1833,7 @@ class ChoicesWidget extends Widget {
             $values = array($values => $this->field->getChoice($values));
         }
 
-        if ($values === null)
+        if (!is_array($values))
             $values = $have_def ? array($def_key => $choices[$def_key]) : array();
 
         ?>