diff --git a/pear/DB.php b/pear/DB.php
index 788aed02fc8..3c706c0aac3 100644
--- a/pear/DB.php
+++ b/pear/DB.php
@@ -242,9 +242,10 @@ class DB
      */
     function isError($value)
     {
-	return is_object($value) &&
-	    (get_class($value) == "db_error" ||
-	     is_subclass_of($value, "db_error"));
+	return (is_object($value) &&
+		(get_class($value) == "db_error" ||
+		 is_subclass_of($value, "db_error")) ||
+		!isset($value));
     }
 
     /**