diff --git a/packages/backend/src/core/entities/UserEntityService.ts b/packages/backend/src/core/entities/UserEntityService.ts
index d4769d24d4..6abf205a56 100644
--- a/packages/backend/src/core/entities/UserEntityService.ts
+++ b/packages/backend/src/core/entities/UserEntityService.ts
@@ -481,6 +481,7 @@ export class UserEntityService implements OnModuleInit {
 
 		const notificationsInfo = isMe && isDetailed ? await this.getNotificationsInfo(user.id) : null;
 
+		// TODO: 例えば avatarUrl: true など間違った型を設定しても型エラーにならないのをどうにかする(ジェネリクス使わない方法で実装するしかなさそう？)
 		const packed = {
 			id: user.id,
 			name: user.name,
diff --git a/packages/backend/src/models/json-schema/user.ts b/packages/backend/src/models/json-schema/user.ts
index 2b5f706ff9..9c88a078c0 100644
--- a/packages/backend/src/models/json-schema/user.ts
+++ b/packages/backend/src/models/json-schema/user.ts
@@ -65,7 +65,7 @@ export const packedUserLiteSchema = {
 		avatarUrl: {
 			type: 'string',
 			format: 'url',
-			nullable: true, optional: false,
+			nullable: false, optional: false,
 		},
 		avatarBlurhash: {
 			type: 'string',
diff --git a/packages/frontend/src/components/MkFlashPreview.vue b/packages/frontend/src/components/MkFlashPreview.vue
index f8f6143a7c..b7278ac742 100644
--- a/packages/frontend/src/components/MkFlashPreview.vue
+++ b/packages/frontend/src/components/MkFlashPreview.vue
@@ -13,7 +13,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			<Mfm class="summaryMfm" :text="flash.summary" :plain="true" :nowrap="true"/>
 		</p>
 		<footer>
-			<img v-if="flash.user.avatarUrl != null" class="icon" :src="flash.user.avatarUrl"/>
+			<img class="icon" :src="flash.user.avatarUrl"/>
 			<p>{{ userName(flash.user) }}</p>
 		</footer>
 	</article>
diff --git a/packages/frontend/src/components/global/RouterView.vue b/packages/frontend/src/components/global/RouterView.vue
index 27f7b18559..3a508eaca0 100644
--- a/packages/frontend/src/components/global/RouterView.vue
+++ b/packages/frontend/src/components/global/RouterView.vue
@@ -30,19 +30,21 @@ const props = defineProps<{
 	router?: Router;
 }>();
 
-const router = props.router ?? inject(DI.router);
+const _router = props.router ?? inject(DI.router);
 
-if (router == null) {
+if (_router == null) {
 	throw new Error('no router provided');
 }
 
+const router = _router;
+
 const viewId = randomId();
 provide(DI.viewId, viewId);
 
 const currentDepth = inject(DI.routerCurrentDepth, 0);
 provide(DI.routerCurrentDepth, currentDepth + 1);
 
-const current = router.current!;
+const current = router.current;
 const currentPageComponent = shallowRef('component' in current.route ? current.route.component : MkLoadingPage);
 const currentPageProps = ref(current.props);
 let currentRoutePath = current.route.path;