diff --git a/api/src/Contacts/Photo.php b/api/src/Contacts/Photo.php
index 7f43231f98..dc185798dc 100644
--- a/api/src/Contacts/Photo.php
+++ b/api/src/Contacts/Photo.php
@@ -108,8 +108,8 @@ class Photo
 			return 'https://gravatar.com/'.md5(trim(strtolower($this->contact)));
 		}
 		return Api\Framework::getUrl(Api\Egw::link('/api/anon_lavatar.php', [
-			'firstname' => $this->contact['firstname'],
-			'lastname'  => $this->contact['lastname'],
+			'firstname' => $this->contact['n_given'],
+			'lastname'  => $this->contact['n_family'],
 			'id'        => $this->contact['id'],
 		]));
 	}
diff --git a/calendar/inc/class.calendar_boupdate.inc.php b/calendar/inc/class.calendar_boupdate.inc.php
index d12b0525bf..9973f55592 100644
--- a/calendar/inc/class.calendar_boupdate.inc.php
+++ b/calendar/inc/class.calendar_boupdate.inc.php
@@ -250,7 +250,7 @@ class calendar_boupdate extends calendar_bo
 		{
 			$event['##videoconference'] = EGroupware\Status\Videoconference\Call::genUniqueRoomID();
 		}
-		elseif(empty($event['videoconference']))
+		elseif (isset($event['videoconference']) && !$event['videoconference'])
 		{
 			$event['##videoconference'] = '';
 		}
@@ -964,7 +964,7 @@ class calendar_boupdate extends calendar_bo
 				continue;	// dont notify rejected participants or groups
 			}
 
-			if($userid != $GLOBALS['egw_info']['user']['account_id'] ||
+			if ($userid != $GLOBALS['egw_info']['user']['account_id'] ||
 				($userid == $GLOBALS['egw_info']['user']['account_id'] &&
 					$user_prefs['calendar']['receive_own_updates']==1) ||
 				$msg_type == MSG_ALARM)
diff --git a/calendar/inc/class.calendar_uiforms.inc.php b/calendar/inc/class.calendar_uiforms.inc.php
index 1f5f506f62..1d0f299642 100644
--- a/calendar/inc/class.calendar_uiforms.inc.php
+++ b/calendar/inc/class.calendar_uiforms.inc.php
@@ -241,13 +241,25 @@ class calendar_uiforms extends calendar_ui
 			$offset = 60 * $this->cal_prefs[$alarm_pref];
 			$alarms[1] =  array(
 				'default' => 1,
-				'offset' => $offset ,
+				'offset' => $offset,
 				'time'   => $start - $offset,
 				'all'    => false,
 				'owner'  => $owner,
 				'id'	=> 1,
 			);
 		}
+		// add automatic alarm 5min before videoconference for all participants
+		if (!empty($_GET['videoconference']))
+		{
+			$offset = -5 * 60;
+			$alarms[1+count($alarms)] =  array(
+				'offset' => $offset,
+				'time'   => $start - $offset,
+				'all'    => true,
+				'owner'  => $owner,
+				'id'	=> 2,
+			);
+		}
 
 		return array(
 			'participant_types' => $participant_types,
diff --git a/calendar/js/app.js b/calendar/js/app.js
index b0a6ecfee7..ef70eb3e06 100644
--- a/calendar/js/app.js
+++ b/calendar/js/app.js
@@ -4180,6 +4180,25 @@ app.classes.calendar = (function(){ "use strict"; return AppJS.extend(
 				}
 			}
 		}
+	},
+
+	/**
+	 * Videoconference checkbox checked
+	 */
+	videoconferenceOnChange: function()
+	{
+		let widget = this.et2.getWidgetById('videoconference');
+
+		if (widget && widget.get_value())
+		{
+			// notify all participants
+			this.et2.getWidgetById('participants[notify_externals]').set_value('yes');
+
+			// add alarm for all participants 5min before videoconference
+			this.et2.getWidgetById('new_alarm[options]').set_value('300');
+			this.et2.getWidgetById('new_alarm[owner]').set_value('0');	// all participants
+			this.et2.getWidgetById('button[add_alarm]').click();
+		}
 	}
 });}).call(this);
 
diff --git a/calendar/templates/default/edit.xet b/calendar/templates/default/edit.xet
index 0c765c776d..e9dac0c640 100644
--- a/calendar/templates/default/edit.xet
+++ b/calendar/templates/default/edit.xet
@@ -233,7 +233,7 @@
 					<label for="location" value="Location"/>
 					<hbox span="2">
 						<textbox id="location" maxlength="255" class="et2_fullWidth"/>
-						<checkbox label="Videoconference" id="videoconference" onchange="if (this.checked) document.getElementById('calendar-edit_notify_externals').value='yes';"/>
+						<checkbox label="Videoconference" id="videoconference" onchange="app.calendar.videoconferenceOnChange"/>
 					</hbox>
 					<description/>
 					<taglist-cat id="category" height="190" empty_label="Categories" multiple="toggle" class="et2_fullWidth" rows="1" />