diff --git a/CHANGELOG.md b/CHANGELOG.md
index b5a5c770..9ddc0ef9 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@ _This release is scheduled to be released on 2021-04-01._
 - Portuguese translations for "MODULE_CONFIG_CHANGED" and PRECIP.
 - Respect parameter ColoredSymbolOnly also for custom events
 - Added a new parameter to hide time portion on relative times
+- `module.show` has now the option for a callback on error.
 - Added locale to sample config file
 - Added support for self-signed certificates for the default calendar module (#466)
 
diff --git a/js/main.js b/js/main.js
index 95d546cd..6f5d9484 100644
--- a/js/main.js
+++ b/js/main.js
@@ -295,6 +295,9 @@ var MM = (function () {
 		// Otherwise cancel show action.
 		if (module.lockStrings.length !== 0 && options.force !== true) {
 			Log.log("Will not show " + module.name + ". LockStrings active: " + module.lockStrings.join(","));
+			if (typeof options.onError === "function") {
+				options.onError(new Error("LOCK_STRING_ACTIVE"));
+			}
 			return;
 		}
 
diff --git a/js/module.js b/js/module.js
index f5cbf86f..042b674b 100644
--- a/js/module.js
+++ b/js/module.js
@@ -428,12 +428,11 @@ var Module = Class.extend({
 		callback = callback || function () {};
 		options = options || {};
 
-		var self = this;
 		MM.showModule(
 			this,
 			speed,
-			function () {
-				self.resume();
+			() => {
+				this.resume();
 				callback();
 			},
 			options