diff --git a/calendar/inc/class.calendar_ui.inc.php b/calendar/inc/class.calendar_ui.inc.php
index b07dcd1879..45eab2d6b0 100644
--- a/calendar/inc/class.calendar_ui.inc.php
+++ b/calendar/inc/class.calendar_ui.inc.php
@@ -560,13 +560,21 @@ class calendar_ui
 			array('value' => 'no-enum-groups', 'label' => lang('only group-events'),'title' => lang('Do not include events of group members')),
 			array('value' => 'not-unknown', 'label' => lang('No meeting requests'),'title' => lang('Show all status, but unknown')),
 		);
-		$sel_options['status_filter'][] = array('value' => 'deleted', 'label' => lang('Deleted'), 'title' => lang('Show events that have been deleted'));
+		$sel_options['status_filter'][] = array(
+			'value' => 'deleted', 'label' => lang('Deleted'),
+			'title' => lang('Show events that have been deleted')
+		);
+
+		$sel_options['cat_id'] = array(
+			['value' => '0', 'label' => lang('None')]
+		);
 
 		// Merge print
-		try {
-			if (class_exists('EGroupware\\collabora\\Bo') &&
-					$GLOBALS['egw_info']['user']['apps']['collabora'] &&
-					$discovery = \EGroupware\collabora\Bo::discover()
+		try
+		{
+			if(class_exists('EGroupware\\collabora\\Bo') &&
+				$GLOBALS['egw_info']['user']['apps']['collabora'] &&
+				$discovery = \EGroupware\collabora\Bo::discover()
 			)
 			{
 				$cont['collabora_enabled'] = true;
diff --git a/calendar/templates/default/sidebox.xet b/calendar/templates/default/sidebox.xet
index 10fbf073f9..77ae090e78 100644
--- a/calendar/templates/default/sidebox.xet
+++ b/calendar/templates/default/sidebox.xet
@@ -18,9 +18,7 @@ Egroupware
             <et2-textbox type="hidden" id="first"></et2-textbox>
             <et2-textbox type="hidden" id="last"></et2-textbox>
             <hrule/>
-            <et2-select-cat id="cat_id" placeholder="All categories" onchange="app.calendar.update_state({cat_id: widget.getValue()});" emptyLabel="All categories" multiple="true">
-                <option value="0">None</option>
-            </et2-select-cat>
+            <et2-select-cat id="cat_id" placeholder="All categories" onchange="app.calendar.update_state({cat_id: widget.getValue()});" emptyLabel="All categories" multiple="true"></et2-select-cat>
             <et2-select id="status_filter" onchange="app.calendar.update_state({status_filter: widget.getValue()});" noLang="true"></et2-select>
             <hrule/>
             <et2-calendar-owner id="owner" onchange="app.calendar.update_state({owner: widget.getValue()}); return false;" multiple="true" allowFreeEntries="false" autocompleteParams="{&quot;checkgrants&quot;: true}"/>