diff --git a/plugins/calendar/calendar.php b/plugins/calendar/calendar.php
index 9bc6be5f..a17cac02 100644
--- a/plugins/calendar/calendar.php
+++ b/plugins/calendar/calendar.php
@@ -1131,9 +1131,9 @@ class calendar extends rcube_plugin
 
     foreach ($this->driver->list_calendars(true) as $cal) {
       $events = $this->driver->load_events(
-        get_input_value('start', RCUBE_INPUT_GET),
-        get_input_value('end', RCUBE_INPUT_GET),
-        get_input_value('q', RCUBE_INPUT_GET),
+        get_input_value('start', RCUBE_INPUT_GPC),
+        get_input_value('end', RCUBE_INPUT_GPC),
+        get_input_value('q', RCUBE_INPUT_GPC),
         $cal['id'],
         1,
         $attr['last']