diff --git a/CHANGELOG.md b/CHANGELOG.md
index e0b60007..b5a5c770 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -20,6 +20,7 @@ _This release is scheduled to be released on 2021-04-01._
 - Respect parameter ColoredSymbolOnly also for custom events
 - Added a new parameter to hide time portion on relative times
 - Added locale to sample config file
+- Added support for self-signed certificates for the default calendar module (#466)
 
 ### Updated
 
diff --git a/modules/default/calendar/calendar.js b/modules/default/calendar/calendar.js
index a4346c64..2cce00c7 100755
--- a/modules/default/calendar/calendar.js
+++ b/modules/default/calendar/calendar.js
@@ -58,7 +58,8 @@ Module.register("calendar", {
 		excludedEvents: [],
 		sliceMultiDayEvents: false,
 		broadcastPastEvents: false,
-		nextDaysRelative: false
+		nextDaysRelative: false,
+		selfSignedCert: false
 	},
 
 	requiresVersion: "2.1.0",
@@ -101,7 +102,8 @@ Module.register("calendar", {
 			var calendarConfig = {
 				maximumEntries: calendar.maximumEntries,
 				maximumNumberOfDays: calendar.maximumNumberOfDays,
-				broadcastPastEvents: calendar.broadcastPastEvents
+				broadcastPastEvents: calendar.broadcastPastEvents,
+				selfSignedCert: calendar.selfSignedCert
 			};
 			if (calendar.symbolClass === "undefined" || calendar.symbolClass === null) {
 				calendarConfig.symbolClass = "";
@@ -606,7 +608,8 @@ Module.register("calendar", {
 			titleClass: calendarConfig.titleClass,
 			timeClass: calendarConfig.timeClass,
 			auth: auth,
-			broadcastPastEvents: calendarConfig.broadcastPastEvents || this.config.broadcastPastEvents
+			broadcastPastEvents: calendarConfig.broadcastPastEvents || this.config.broadcastPastEvents,
+			selfSignedCert: calendarConfig.selfSignedCert || this.config.selfSignedCert
 		});
 	},
 
diff --git a/modules/default/calendar/calendarfetcher.js b/modules/default/calendar/calendarfetcher.js
index 55e5cdaa..73f92b1e 100644
--- a/modules/default/calendar/calendarfetcher.js
+++ b/modules/default/calendar/calendarfetcher.js
@@ -25,9 +25,10 @@ const moment = require("moment");
  * @param {number} maximumNumberOfDays The maximum number of days an event should be in the future.
  * @param {object} auth The object containing options for authentication against the calendar.
  * @param {boolean} includePastEvents If true events from the past maximumNumberOfDays will be fetched too
+ * @param {boolean} selfSignedCert If true, the server certificate is not verified against the list of supplied CAs.
  * @class
  */
-const CalendarFetcher = function (url, reloadInterval, excludedEvents, maximumEntries, maximumNumberOfDays, auth, includePastEvents) {
+const CalendarFetcher = function (url, reloadInterval, excludedEvents, maximumEntries, maximumNumberOfDays, auth, includePastEvents, selfSignedCert) {
 	const self = this;
 
 	let reloadTimer = null;
@@ -51,6 +52,13 @@ const CalendarFetcher = function (url, reloadInterval, excludedEvents, maximumEn
 			gzip: true
 		};
 
+		if (selfSignedCert) {
+			var agentOptions = {
+				rejectUnauthorized: false
+			};
+			opts.agentOptions = agentOptions;
+		}
+
 		if (auth) {
 			if (auth.method === "bearer") {
 				opts.auth = {
diff --git a/modules/default/calendar/node_helper.js b/modules/default/calendar/node_helper.js
index c44e91fc..e1813737 100644
--- a/modules/default/calendar/node_helper.js
+++ b/modules/default/calendar/node_helper.js
@@ -19,7 +19,7 @@ module.exports = NodeHelper.create({
 	// Override socketNotificationReceived method.
 	socketNotificationReceived: function (notification, payload) {
 		if (notification === "ADD_CALENDAR") {
-			this.createFetcher(payload.url, payload.fetchInterval, payload.excludedEvents, payload.maximumEntries, payload.maximumNumberOfDays, payload.auth, payload.broadcastPastEvents, payload.id);
+			this.createFetcher(payload.url, payload.fetchInterval, payload.excludedEvents, payload.maximumEntries, payload.maximumNumberOfDays, payload.auth, payload.broadcastPastEvents, payload.selfSignedCert, payload.id);
 		}
 	},
 
@@ -34,9 +34,10 @@ module.exports = NodeHelper.create({
 	 * @param {number} maximumNumberOfDays The maximum number of days an event should be in the future.
 	 * @param {object} auth The object containing options for authentication against the calendar.
 	 * @param {boolean} broadcastPastEvents If true events from the past maximumNumberOfDays will be included in event broadcasts
+	 * @param {boolean} selfSignedCert If true, the server certificate is not verified against the list of supplied CAs.
 	 * @param {string} identifier ID of the module
 	 */
-	createFetcher: function (url, fetchInterval, excludedEvents, maximumEntries, maximumNumberOfDays, auth, broadcastPastEvents, identifier) {
+	createFetcher: function (url, fetchInterval, excludedEvents, maximumEntries, maximumNumberOfDays, auth, broadcastPastEvents, selfSignedCert, identifier) {
 		var self = this;
 
 		if (!validUrl.isUri(url)) {
@@ -47,7 +48,7 @@ module.exports = NodeHelper.create({
 		var fetcher;
 		if (typeof self.fetchers[identifier + url] === "undefined") {
 			Log.log("Create new calendar fetcher for url: " + url + " - Interval: " + fetchInterval);
-			fetcher = new CalendarFetcher(url, fetchInterval, excludedEvents, maximumEntries, maximumNumberOfDays, auth, broadcastPastEvents);
+			fetcher = new CalendarFetcher(url, fetchInterval, excludedEvents, maximumEntries, maximumNumberOfDays, auth, broadcastPastEvents, selfSignedCert);
 
 			fetcher.onReceive(function (fetcher) {
 				self.sendSocketNotification("CALENDAR_EVENTS", {