diff --git a/wpas.php b/wpas.php
index 95093bc..3f1a027 100644
--- a/wpas.php
+++ b/wpas.php
@@ -216,6 +216,8 @@ function build_form() {
                 $output .= '<input type="hidden" name="orderby" value="'.$this->orderby_relevanssi.'">';
             }
 
+            $output .= '<input type="hidden" name="wpas" value="1">';
+
             $output .= '</form>';
             $this->the_form = $output;
         }