diff --git a/calendar/inc/class.calendar_ui.inc.php b/calendar/inc/class.calendar_ui.inc.php
index 9614dffca4..9c6843a669 100644
--- a/calendar/inc/class.calendar_ui.inc.php
+++ b/calendar/inc/class.calendar_ui.inc.php
@@ -753,7 +753,17 @@ class calendar_ui
 		// set id for grid
 		$event['row_id'] = $event['id'].($event['recur_type'] ? ':'.Api\DateTime::to($event['recur_date'] ? $event['recur_date'] : $event['start'],'ts') : '');
 
-		$event['parts'] = implode(",\n",$this->bo->participants($event,false));
+		// Set up participant section of tooltip
+		$participants = $this->bo->participants($event,false);
+		$event['parts'] = implode("\n",$participants);
+		$event['participant_types'] = array();
+		foreach($participants as $uid => $text)
+		{
+			$user_type = $user_id = null;
+			calendar_so::split_user($uid, $user_type, $user_id);
+			$type_name = lang($this->bo->resources[$user_type]['app']);
+			$event['participant_types'][$type_name ? $type_name : ''][] = $text;
+		}
 		$event['date'] = $this->bo->date2string($event['start']);
 
 		// Change dates
diff --git a/calendar/js/et2_widget_event.js b/calendar/js/et2_widget_event.js
index 5ab70902a4..e34072da89 100644
--- a/calendar/js/et2_widget_event.js
+++ b/calendar/js/et2_widget_event.js
@@ -493,6 +493,15 @@ var et2_calendar_event = (function(){ "use strict"; return et2_valueWidget.exten
 			}
 			cat.destroy();
 		}
+		var participants = '';
+		for(var type_name in this.options.value.participant_types)
+		{
+			if(type_name)
+			{
+				participants += '</p><p><span class="calendar_calEventLabel">'+type_name+'</span>:<br />';
+			}
+			participants += this.options.value.participant_types[type_name].join("<br />");
+		}
 
 		return '<div class="calendar_calEventTooltip ' + this._status_class() +' '+ this.options.class +
 			'" style="border-color: '+border+'; background-color: '+bg_color+';">'+
@@ -508,7 +517,7 @@ var et2_calendar_event = (function(){ "use strict"; return et2_valueWidget.exten
 				(this.options.value.location ? '<p><span class="calendar_calEventLabel">'+this.egw().lang('Location') + '</span>:' + this.options.value.location+'</p>' : '')+
 				(cat_label ? '<p><span class="calendar_calEventLabel">'+this.egw().lang('Category') + '</span>:' + cat_label +'</p>' : '')+
 				'<p><span class="calendar_calEventLabel">'+this.egw().lang('Participants')+'</span>:<br />'+
-					(this.options.value.parts ? this.options.value.parts.replace("\n","<br />"):'')+'</p>'+
+					participants + '</p>'+
 			'</div>'+
 		'</div>';
 	},