diff --git a/packages/backend/src/core/entities/UserEntityService.ts b/packages/backend/src/core/entities/UserEntityService.ts
index 64aec65205..17e7988176 100644
--- a/packages/backend/src/core/entities/UserEntityService.ts
+++ b/packages/backend/src/core/entities/UserEntityService.ts
@@ -471,7 +471,7 @@ export class UserEntityService implements OnModuleInit {
 				hasUnreadChannel: false, // 後方互換性のため
 				hasUnreadNotification: notificationsInfo?.hasUnread, // 後方互換性のため
 				hasPendingReceivedFollowRequest: this.getHasPendingReceivedFollowRequest(user.id),
-				unreadNotificationCount: notificationsInfo?.unreadCount,
+				unreadNotificationsCount: notificationsInfo?.unreadCount,
 				mutedWords: profile!.mutedWords,
 				mutedInstances: profile!.mutedInstances,
 				mutingNotificationTypes: [], // 後方互換性のため
diff --git a/packages/backend/src/models/json-schema/user.ts b/packages/backend/src/models/json-schema/user.ts
index edb780272a..37bdcbe281 100644
--- a/packages/backend/src/models/json-schema/user.ts
+++ b/packages/backend/src/models/json-schema/user.ts
@@ -399,7 +399,7 @@ export const packedMeDetailedOnlySchema = {
 			type: 'boolean',
 			nullable: false, optional: false,
 		},
-		unreadNotificationCount: {
+		unreadNotificationsCount: {
 			type: 'number',
 			nullable: false, optional: false,
 		},
diff --git a/packages/backend/test/e2e/users.ts b/packages/backend/test/e2e/users.ts
index a089b265ad..1867525cc8 100644
--- a/packages/backend/test/e2e/users.ts
+++ b/packages/backend/test/e2e/users.ts
@@ -164,7 +164,7 @@ describe('ユーザー', () => {
 			hasUnreadAntenna: user.hasUnreadAntenna,
 			hasUnreadChannel: user.hasUnreadChannel,
 			hasUnreadNotification: user.hasUnreadNotification,
-			unreadNotificationCount: user.unreadNotificationCount,
+			unreadNotificationsCount: user.unreadNotificationsCount,
 			hasPendingReceivedFollowRequest: user.hasPendingReceivedFollowRequest,
 			unreadAnnouncements: user.unreadAnnouncements,
 			mutedWords: user.mutedWords,
@@ -415,7 +415,7 @@ describe('ユーザー', () => {
 		assert.strictEqual(response.hasUnreadAntenna, false);
 		assert.strictEqual(response.hasUnreadChannel, false);
 		assert.strictEqual(response.hasUnreadNotification, false);
-		assert.strictEqual(response.unreadNotificationCount, 0);
+		assert.strictEqual(response.unreadNotificationsCount, 0);
 		assert.strictEqual(response.hasPendingReceivedFollowRequest, false);
 		assert.deepStrictEqual(response.unreadAnnouncements, []);
 		assert.deepStrictEqual(response.mutedWords, []);
diff --git a/packages/frontend/src/boot/main-boot.ts b/packages/frontend/src/boot/main-boot.ts
index c35f2fdc4d..b11d0db043 100644
--- a/packages/frontend/src/boot/main-boot.ts
+++ b/packages/frontend/src/boot/main-boot.ts
@@ -228,15 +228,15 @@ export async function mainBoot() {
 		main.on('readAllNotifications', () => {
 			updateAccount({
 				hasUnreadNotification: false,
-				unreadNotificationCount: 0,
+				unreadNotificationsCount: 0,
 			});
 		});
 
 		main.on('unreadNotification', () => {
-			const unreadNotificationCount = ($i?.unreadNotificationCount ?? 0) + 1;
+			const unreadNotificationsCount = ($i?.unreadNotificationsCount ?? 0) + 1;
 			updateAccount({
 				hasUnreadNotification: true,
-				unreadNotificationCount,
+				unreadNotificationsCount,
 			});
 		});
 
diff --git a/packages/frontend/src/navbar.ts b/packages/frontend/src/navbar.ts
index 22ee0a8263..f0ed773f82 100644
--- a/packages/frontend/src/navbar.ts
+++ b/packages/frontend/src/navbar.ts
@@ -20,12 +20,12 @@ export const navbarItemDef = reactive({
 		show: computed(() => $i != null),
 		indicated: computed(() => $i != null && $i.hasUnreadNotification),
 		indicateValue: computed(() => {
-			if (!$i || $i.unreadNotificationCount === 0) return '';
+			if (!$i || $i.unreadNotificationsCount === 0) return '';
 
-			if ($i.unreadNotificationCount > 99) {
+			if ($i.unreadNotificationsCount > 99) {
 				return '99+';
 			} else {
-				return $i.unreadNotificationCount.toString();
+				return $i.unreadNotificationsCount.toString();
 			}
 		}),
 		to: '/my/notifications',
diff --git a/packages/frontend/src/ui/deck.vue b/packages/frontend/src/ui/deck.vue
index 69f1613e62..1d51e08f78 100644
--- a/packages/frontend/src/ui/deck.vue
+++ b/packages/frontend/src/ui/deck.vue
@@ -55,7 +55,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 		<button :class="$style.navButton" class="_button" @click="mainRouter.push('/my/notifications')">
 			<i :class="$style.navButtonIcon" class="ti ti-bell"></i>
 			<span v-if="$i?.hasUnreadNotification" :class="$style.navButtonIndicator">
-				<span class="_indicateCounter" :class="$style.itemIndicateValueIcon">{{ $i.unreadNotificationCount > 99 ? '99+' : $i.unreadNotificationCount }}</span>
+				<span class="_indicateCounter" :class="$style.itemIndicateValueIcon">{{ $i.unreadNotificationsCount > 99 ? '99+' : $i.unreadNotificationsCount }}</span>
 			</span>
 		</button>
 		<button :class="$style.postButton" class="_button" @click="os.post()"><i :class="$style.navButtonIcon" class="ti ti-pencil"></i></button>
diff --git a/packages/frontend/src/ui/universal.vue b/packages/frontend/src/ui/universal.vue
index 2dafd4e6eb..86ec8650f9 100644
--- a/packages/frontend/src/ui/universal.vue
+++ b/packages/frontend/src/ui/universal.vue
@@ -30,7 +30,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 		<button :class="$style.navButton" class="_button" @click="mainRouter.push('/my/notifications')">
 			<i :class="$style.navButtonIcon" class="ti ti-bell"></i>
 			<span v-if="$i?.hasUnreadNotification" :class="$style.navButtonIndicator">
-				<span class="_indicateCounter" :class="$style.itemIndicateValueIcon">{{ $i.unreadNotificationCount > 99 ? '99+' : $i.unreadNotificationCount }}</span>
+				<span class="_indicateCounter" :class="$style.itemIndicateValueIcon">{{ $i.unreadNotificationsCount > 99 ? '99+' : $i.unreadNotificationsCount }}</span>
 			</span>
 		</button>
 		<button :class="$style.navButton" class="_button" @click="widgetsShowing = true"><i :class="$style.navButtonIcon" class="ti ti-apps"></i></button>
diff --git a/packages/misskey-js/etc/misskey-js.api.md b/packages/misskey-js/etc/misskey-js.api.md
index b9aa08be76..8f389086c9 100644
--- a/packages/misskey-js/etc/misskey-js.api.md
+++ b/packages/misskey-js/etc/misskey-js.api.md
@@ -2488,7 +2488,7 @@ type MeDetailed = UserDetailed & {
     hasUnreadMessagingMessage: boolean;
     hasUnreadNotification: boolean;
     hasUnreadSpecifiedNotes: boolean;
-    unreadNotificationCount: number;
+    unreadNotificationsCount: number;
     hideOnlineStatus: boolean;
     injectFeaturedNote: boolean;
     integrations: Record<string, any>;
diff --git a/packages/misskey-js/src/entities.ts b/packages/misskey-js/src/entities.ts
index 6fe3a49242..029bf48c84 100644
--- a/packages/misskey-js/src/entities.ts
+++ b/packages/misskey-js/src/entities.ts
@@ -106,7 +106,7 @@ export type MeDetailed = UserDetailed & {
 	hasUnreadMessagingMessage: boolean;
 	hasUnreadNotification: boolean;
 	hasUnreadSpecifiedNotes: boolean;
-	unreadNotificationCount: number;
+	unreadNotificationsCount: number;
 	hideOnlineStatus: boolean;
 	injectFeaturedNote: boolean;
 	integrations: Record<string, any>;