diff --git a/packages/frontend-embed/src/components/EmNote.vue b/packages/frontend-embed/src/components/EmNote.vue
index a918ae8db4..bf96c557ea 100644
--- a/packages/frontend-embed/src/components/EmNote.vue
+++ b/packages/frontend-embed/src/components/EmNote.vue
@@ -109,7 +109,7 @@ import * as mfm from '@transfem-org/sfm-js';
 import * as Misskey from 'misskey-js';
 import { shouldCollapsed } from '@@/js/collapsed.js';
 import { url } from '@@/js/config.js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import I18n from '@/components/I18n.vue';
 import EmNoteSub from '@/components/EmNoteSub.vue';
 import EmNoteHeader from '@/components/EmNoteHeader.vue';
@@ -156,13 +156,7 @@ const isLong = shouldCollapsed(appearNote.value, []);
 const collapsed = ref(appearNote.value.cw == null && isLong);
 const isDeleted = ref(false);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 </script>
 
 <style lang="scss" module>
diff --git a/packages/frontend-embed/src/components/EmNoteDetailed.vue b/packages/frontend-embed/src/components/EmNoteDetailed.vue
index 10a58feaef..0961b36e35 100644
--- a/packages/frontend-embed/src/components/EmNoteDetailed.vue
+++ b/packages/frontend-embed/src/components/EmNoteDetailed.vue
@@ -130,7 +130,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 import { computed, inject, ref } from 'vue';
 import * as mfm from '@transfem-org/sfm-js';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import I18n from '@/components/I18n.vue';
 import EmMediaList from '@/components/EmMediaList.vue';
 import EmNoteSub from '@/components/EmNoteSub.vue';
@@ -177,13 +177,7 @@ const parsed = appearNote.value.text ? mfm.parse(appearNote.value.text) : null;
 const isLong = shouldCollapsed(appearNote.value, []);
 const collapsed = ref(appearNote.value.cw == null && isLong);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 </script>
 
 <style lang="scss" module>
diff --git a/packages/frontend-embed/src/components/EmNoteSimple.vue b/packages/frontend-embed/src/components/EmNoteSimple.vue
index 74aed4e28b..688758edb6 100644
--- a/packages/frontend-embed/src/components/EmNoteSimple.vue
+++ b/packages/frontend-embed/src/components/EmNoteSimple.vue
@@ -24,7 +24,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { computed, ref } from 'vue';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import { i18n } from '@/i18n.js';
 import EmAvatar from '@/components/EmAvatar.vue';
 import EmNoteHeader from '@/components/EmNoteHeader.vue';
@@ -37,13 +37,7 @@ const props = defineProps<{
 
 const showContent = ref(false);
 
-const mergedCW = computed(() => {
-	let cw = props.note.cw;
-	if (props.note.user.mandatoryCW) {
-		cw = appendContentWarning(cw, props.note.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(props.note));
 </script>
 
 <style lang="scss" module>
diff --git a/packages/frontend-embed/src/components/EmNoteSub.vue b/packages/frontend-embed/src/components/EmNoteSub.vue
index e1302bbe25..629f0bffcd 100644
--- a/packages/frontend-embed/src/components/EmNoteSub.vue
+++ b/packages/frontend-embed/src/components/EmNoteSub.vue
@@ -33,7 +33,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { computed, ref } from 'vue';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import EmA from '@/components/EmA.vue';
 import EmAvatar from '@/components/EmAvatar.vue';
 import EmNoteHeader from '@/components/EmNoteHeader.vue';
@@ -56,13 +56,7 @@ const props = withDefaults(defineProps<{
 const showContent = ref(false);
 const replies = ref<Misskey.entities.Note[]>([]);
 
-const mergedCW = computed(() => {
-	let cw = props.note.cw;
-	if (props.note.user.mandatoryCW) {
-		cw = appendContentWarning(cw, props.note.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(props.note));
 
 if (props.detail) {
 	misskeyApi('notes/children', {
diff --git a/packages/frontend-shared/js/compute-merged-cw.ts b/packages/frontend-shared/js/compute-merged-cw.ts
new file mode 100644
index 0000000000..aafe141b69
--- /dev/null
+++ b/packages/frontend-shared/js/compute-merged-cw.ts
@@ -0,0 +1,17 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import * as Misskey from 'misskey-js';
+import { appendContentWarning } from '@/js/append-content-warning.js';
+
+export function computeMergedCw(note: Misskey.entities.Note): string | null {
+	let cw = note.cw;
+
+	if (note.user.mandatoryCW) {
+		cw = appendContentWarning(cw, note.user.mandatoryCW);
+	}
+
+	return cw ?? null;
+}
diff --git a/packages/frontend/src/components/MkNote.vue b/packages/frontend/src/components/MkNote.vue
index aa971b0ab3..0bac6a67b9 100644
--- a/packages/frontend/src/components/MkNote.vue
+++ b/packages/frontend/src/components/MkNote.vue
@@ -212,7 +212,7 @@ import * as Misskey from 'misskey-js';
 import { isLink } from '@@/js/is-link.js';
 import { shouldCollapsed } from '@@/js/collapsed.js';
 import { host } from '@@/js/config.js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import type { MenuItem } from '@/types/menu.js';
 import MkNoteSub from '@/components/MkNoteSub.vue';
 import MkNoteHeader from '@/components/MkNoteHeader.vue';
@@ -351,13 +351,7 @@ const pleaseLoginContext = computed<OpenOnRemoteOptions>(() => ({
 	url: `https://${host}/notes/${appearNote.value.id}`,
 }));
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 
 const renoteTooltip = computeRenoteTooltip(renoted);
 
diff --git a/packages/frontend/src/components/MkNoteDetailed.vue b/packages/frontend/src/components/MkNoteDetailed.vue
index 5f7c4fa12f..582838ebca 100644
--- a/packages/frontend/src/components/MkNoteDetailed.vue
+++ b/packages/frontend/src/components/MkNoteDetailed.vue
@@ -245,7 +245,7 @@ import * as mfm from '@transfem-org/sfm-js';
 import * as Misskey from 'misskey-js';
 import { isLink } from '@@/js/is-link.js';
 import { host } from '@@/js/config.js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import MkNoteSub from '@/components/MkNoteSub.vue';
 import MkNoteSimple from '@/components/MkNoteSimple.vue';
 import MkReactionsViewer from '@/components/MkReactionsViewer.vue';
@@ -349,13 +349,7 @@ const quotes = ref<Misskey.entities.Note[]>([]);
 const canRenote = computed(() => ['public', 'home'].includes(appearNote.value.visibility) || (appearNote.value.visibility === 'followers' && appearNote.value.userId === $i?.id));
 const defaultLike = computed(() => defaultStore.state.like ? defaultStore.state.like : null);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 
 const renoteTooltip = computeRenoteTooltip(renoted);
 
diff --git a/packages/frontend/src/components/MkNoteSimple.vue b/packages/frontend/src/components/MkNoteSimple.vue
index e487fb978e..3720aa7493 100644
--- a/packages/frontend/src/components/MkNoteSimple.vue
+++ b/packages/frontend/src/components/MkNoteSimple.vue
@@ -28,7 +28,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { computed, ref, watch } from 'vue';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import * as os from '@/os.js';
 import MkNoteHeader from '@/components/MkNoteHeader.vue';
 import MkSubNoteContent from '@/components/MkSubNoteContent.vue';
@@ -49,13 +49,7 @@ const props = defineProps<{
 let showContent = ref(defaultStore.state.uncollapseCW);
 const isDeleted = ref(false);
 
-const mergedCW = computed(() => {
-	let cw = props.note.cw;
-	if (props.note.user.mandatoryCW) {
-		cw = appendContentWarning(cw, props.note.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(props.note));
 
 const emit = defineEmits<{
 	(ev: 'editScheduleNote'): void;
diff --git a/packages/frontend/src/components/MkNoteSub.vue b/packages/frontend/src/components/MkNoteSub.vue
index 43cc35d3cc..61006cfdcc 100644
--- a/packages/frontend/src/components/MkNoteSub.vue
+++ b/packages/frontend/src/components/MkNoteSub.vue
@@ -86,7 +86,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { computed, ref, shallowRef, watch } from 'vue';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import MkNoteHeader from '@/components/MkNoteHeader.vue';
 import MkReactionsViewer from '@/components/MkReactionsViewer.vue';
 import MkSubNoteContent from '@/components/MkSubNoteContent.vue';
@@ -143,13 +143,7 @@ let appearNote = computed(() => isRenote ? props.note.renote as Misskey.entities
 const defaultLike = computed(() => defaultStore.state.like ? defaultStore.state.like : null);
 const replies = ref<Misskey.entities.Note[]>([]);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 
 const isRenote = (
 	props.note.renote != null &&
diff --git a/packages/frontend/src/components/SkNote.vue b/packages/frontend/src/components/SkNote.vue
index 2cfc5ac01e..777e95593d 100644
--- a/packages/frontend/src/components/SkNote.vue
+++ b/packages/frontend/src/components/SkNote.vue
@@ -213,7 +213,7 @@ import * as Misskey from 'misskey-js';
 import { isLink } from '@@/js/is-link.js';
 import { shouldCollapsed } from '@@/js/collapsed.js';
 import { host } from '@@/js/config.js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import type { MenuItem } from '@/types/menu.js';
 import SkNoteSub from '@/components/SkNoteSub.vue';
 import SkNoteHeader from '@/components/SkNoteHeader.vue';
@@ -346,13 +346,7 @@ const defaultLike = computed(() => defaultStore.state.like ? defaultStore.state.
 const animated = computed(() => parsed.value ? checkAnimationFromMfm(parsed.value) : null);
 const allowAnim = ref(defaultStore.state.advancedMfm && defaultStore.state.animatedMfm ? true : false);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 
 const renoteTooltip = computeRenoteTooltip(renoted);
 
diff --git a/packages/frontend/src/components/SkNoteDetailed.vue b/packages/frontend/src/components/SkNoteDetailed.vue
index 1931946bcc..471a4ce7d7 100644
--- a/packages/frontend/src/components/SkNoteDetailed.vue
+++ b/packages/frontend/src/components/SkNoteDetailed.vue
@@ -250,7 +250,7 @@ import * as mfm from '@transfem-org/sfm-js';
 import * as Misskey from 'misskey-js';
 import { isLink } from '@@/js/is-link.js';
 import { host } from '@@/js/config.js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import SkNoteSub from '@/components/SkNoteSub.vue';
 import SkNoteSimple from '@/components/SkNoteSimple.vue';
 import MkReactionsViewer from '@/components/MkReactionsViewer.vue';
@@ -355,13 +355,7 @@ const quotes = ref<Misskey.entities.Note[]>([]);
 const canRenote = computed(() => ['public', 'home'].includes(appearNote.value.visibility) || (appearNote.value.visibility === 'followers' && appearNote.value.userId === $i?.id));
 const defaultLike = computed(() => defaultStore.state.like ? defaultStore.state.like : null);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 
 const renoteTooltip = computeRenoteTooltip(renoted);
 
diff --git a/packages/frontend/src/components/SkNoteSimple.vue b/packages/frontend/src/components/SkNoteSimple.vue
index f30fb82926..71a5bd4df8 100644
--- a/packages/frontend/src/components/SkNoteSimple.vue
+++ b/packages/frontend/src/components/SkNoteSimple.vue
@@ -24,7 +24,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { watch, ref, computed } from 'vue';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import MkNoteHeader from '@/components/MkNoteHeader.vue';
 import MkSubNoteContent from '@/components/MkSubNoteContent.vue';
 import MkCwButton from '@/components/MkCwButton.vue';
@@ -38,13 +38,7 @@ const props = defineProps<{
 
 let showContent = ref(defaultStore.state.uncollapseCW);
 
-const mergedCW = computed(() => {
-	let cw = props.note.cw;
-	if (props.note.user.mandatoryCW) {
-		cw = appendContentWarning(cw, props.note.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(props.note));
 
 watch(() => props.expandAllCws, (expandAllCws) => {
 	if (expandAllCws !== showContent.value) showContent.value = expandAllCws;
diff --git a/packages/frontend/src/components/SkNoteSub.vue b/packages/frontend/src/components/SkNoteSub.vue
index a4ab7b7405..060e66be16 100644
--- a/packages/frontend/src/components/SkNoteSub.vue
+++ b/packages/frontend/src/components/SkNoteSub.vue
@@ -94,7 +94,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 <script lang="ts" setup>
 import { computed, ref, shallowRef, watch } from 'vue';
 import * as Misskey from 'misskey-js';
-import { appendContentWarning } from '@@/js/append-content-warning.js';
+import { computeMergedCw } from '@@/js/compute-merged-cw.js';
 import SkNoteHeader from '@/components/SkNoteHeader.vue';
 import MkReactionsViewer from '@/components/MkReactionsViewer.vue';
 import MkSubNoteContent from '@/components/MkSubNoteContent.vue';
@@ -157,13 +157,7 @@ let appearNote = computed(() => isRenote ? props.note.renote as Misskey.entities
 const defaultLike = computed(() => defaultStore.state.like ? defaultStore.state.like : null);
 const replies = ref<Misskey.entities.Note[]>([]);
 
-const mergedCW = computed(() => {
-	let cw = appearNote.value.cw;
-	if (appearNote.value.user.mandatoryCW) {
-		cw = appendContentWarning(cw, appearNote.value.user.mandatoryCW);
-	}
-	return cw;
-});
+const mergedCW = computed(() => computeMergedCw(appearNote.value));
 
 const isRenote = (
 	props.note.renote != null &&