diff --git a/components/apps/Messenger/SanitizedContent.tsx b/components/apps/Messenger/SanitizedContent.tsx
index 22fb2cd2..0f61c5b1 100644
--- a/components/apps/Messenger/SanitizedContent.tsx
+++ b/components/apps/Messenger/SanitizedContent.tsx
@@ -1,4 +1,4 @@
-import { sanitize } from "dompurify";
+import DOMPurify from "dompurify";
 import { useMemo } from "react";
 import {
   convertImageLinksToHtml,
@@ -21,7 +21,7 @@ const SanitizedContent: FC<{ content: string; decrypted: boolean }> = ({
     <div
       // eslint-disable-next-line react/no-danger
       dangerouslySetInnerHTML={{
-        __html: sanitize(decryptedContent || content, {
+        __html: DOMPurify.sanitize(decryptedContent || content, {
           ALLOWED_ATTR: ["src"],
           ALLOWED_TAGS: ["br", "img"],
         }),
diff --git a/components/pages/ErrorBoundary.ts b/components/pages/ErrorBoundary.ts
index 076d7988..8ec83784 100644
--- a/components/pages/ErrorBoundary.ts
+++ b/components/pages/ErrorBoundary.ts
@@ -17,7 +17,7 @@ export class ErrorBoundary extends Component<
     this.state = { hasError: false };
   }
 
-  public shouldComponentUpdate(): boolean {
+  public override shouldComponentUpdate(): boolean {
     return false;
   }
 
@@ -25,7 +25,7 @@ export class ErrorBoundary extends Component<
     return { hasError: true };
   }
 
-  public render(): React.ReactNode {
+  public override render(): React.ReactNode {
     const {
       props: { children, FallbackRender },
       state: { hasError },
diff --git a/pages/_document.tsx b/pages/_document.tsx
index 713f1751..1f3a353c 100644
--- a/pages/_document.tsx
+++ b/pages/_document.tsx
@@ -33,13 +33,13 @@ const withStyledComponents = async (
 };
 
 class Document extends NextDocument {
-  public static async getInitialProps(
+  public static override async getInitialProps(
     ctx: DocumentContext
   ): Promise<DocumentInitialProps> {
     return withStyledComponents(ctx);
   }
 
-  public render(): React.JSX.Element {
+  public override render(): React.JSX.Element {
     return (
       <Html lang={DEFAULT_LOCALE}>
         <Head />
diff --git a/tsconfig.json b/tsconfig.json
index 7c93a4ad..163b222e 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -1,6 +1,7 @@
 {
   "compilerOptions": {
     "allowJs": true,
+    "allowUnreachableCode": false,
     "baseUrl": ".",
     "esModuleInterop": true,
     "forceConsistentCasingInFileNames": true,
@@ -11,6 +12,7 @@
     "module": "esnext",
     "moduleResolution": "node",
     "noEmit": true,
+    "noImplicitOverride": true,
     "noImplicitReturns": true,
     "plugins": [{ "name": "next" }],
     "resolveJsonModule": true,
