diff --git a/CHANGELOG.md b/CHANGELOG.md
index b87a525..ff21ca6 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,10 @@ All notable changes to this project will be documented in this file.
 
 ## \[unreleased]
 
+### 🐛 Bug Fixes
+
+- Update web-ext to support newer browser APIs and remove `addon-linter` override
+
 ### 🚜 Refactor
 
 - Inline `fetch` and use `URLSearchParams`
diff --git a/types.d.ts b/types.d.ts
index 99f2080..f0c5d41 100644
--- a/types.d.ts
+++ b/types.d.ts
@@ -3,17 +3,17 @@ export type Storage = {
 	spaceApi?: SpaceApi | undefined;
 };
 
-export type Calendar = CalendarEntry[];
-type CalendarEntry = {
-	begin: string;
-	begin_date: `${number}.${number}.${number}`;
-	begin_time: `${number}:${number}`;
-	end: string;
-	end_date: `${number}.${number}.${number}`;
-	end_time: `${number}:${number}`;
-	name: string;
-	description: string | null;
-	location: string | null;
+export type Calendar = readonly CalendarEntry[];
+export type CalendarEntry = {
+	readonly begin: string;
+	readonly begin_date: `${number}.${number}.${number}`;
+	readonly begin_time: `${number}:${number}`;
+	readonly end: string;
+	readonly end_date: `${number}.${number}.${number}`;
+	readonly end_time: `${number}:${number}`;
+	readonly name: string;
+	readonly description: string | null;
+	readonly location: string | null;
 };
 
 /**