diff --git a/packages/backend/eslint.config.js b/packages/backend/eslint.config.js
index 7c649a373c..ef5a0ccec1 100644
--- a/packages/backend/eslint.config.js
+++ b/packages/backend/eslint.config.js
@@ -42,13 +42,6 @@ export default [
 				name: '__filename',
 				message: 'Not in ESModule. Use `import.meta.url` instead.',
 			}],
-			// https://typescript-eslint.io/rules/prefer-nullish-coalescing/
-			'@typescript-eslint/prefer-nullish-coalescing': ['warn', {
-				ignorePrimitives: {
-					// Without this, the rule breaks for nullable booleans
-					boolean: true,
-				},
-			}],
 		},
 	},
 	{
diff --git a/packages/backend/src/server/api/endpoints/notes/create.test.ts b/packages/backend/src/server/api/endpoints/notes/create.test.ts
index 18d80e867b..545889a7ee 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.test.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.test.ts
@@ -65,7 +65,7 @@ describe('api:notes/create', () => {
 
 			test('0 characters cw', () => {
 				expect(v({ text: 'Body', cw: '' }))
-					.toBe(INVALID);
+					.toBe(VALID);
 			});
 
 			test('reject only cw', () => {
diff --git a/packages/backend/src/server/api/endpoints/notes/create.ts b/packages/backend/src/server/api/endpoints/notes/create.ts
index b0f32bfda8..3dd90c3dca 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.ts
@@ -159,7 +159,7 @@ export const paramDef = {
 		visibleUserIds: { type: 'array', uniqueItems: true, items: {
 			type: 'string', format: 'misskey:id',
 		} },
-		cw: { type: 'string', nullable: true, minLength: 1 },
+		cw: { type: 'string', nullable: true },
 		localOnly: { type: 'boolean', default: false },
 		reactionAcceptance: { type: 'string', nullable: true, enum: [null, 'likeOnly', 'likeOnlyForRemote', 'nonSensitiveOnly', 'nonSensitiveOnlyForLocalLikeOnlyForRemote'], default: null },
 		noExtractMentions: { type: 'boolean', default: false },
@@ -400,7 +400,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					text: ps.text ?? undefined,
 					reply,
 					renote,
-					cw: ps.cw,
+					cw: ps.cw || null,
 					localOnly: ps.localOnly,
 					reactionAcceptance: ps.reactionAcceptance,
 					visibility: ps.visibility,
diff --git a/packages/backend/src/server/api/endpoints/notes/edit.ts b/packages/backend/src/server/api/endpoints/notes/edit.ts
index cc2293c5d6..7b13d3a4f4 100644
--- a/packages/backend/src/server/api/endpoints/notes/edit.ts
+++ b/packages/backend/src/server/api/endpoints/notes/edit.ts
@@ -209,7 +209,7 @@ export const paramDef = {
 				format: 'misskey:id',
 			},
 		},
-		cw: { type: 'string', nullable: true, minLength: 1 },
+		cw: { type: 'string', nullable: true },
 		localOnly: { type: 'boolean', default: false },
 		reactionAcceptance: { type: 'string', nullable: true, enum: [null, 'likeOnly', 'likeOnlyForRemote', 'nonSensitiveOnly', 'nonSensitiveOnlyForLocalLikeOnlyForRemote'], default: null },
 		noExtractMentions: { type: 'boolean', default: false },
@@ -454,7 +454,7 @@ export default class extends Endpoint<typeof meta, typeof paramDef> { // eslint-
 					text: ps.text ?? undefined,
 					reply,
 					renote,
-					cw: ps.cw,
+					cw: ps.cw || null,
 					localOnly: ps.localOnly,
 					reactionAcceptance: ps.reactionAcceptance,
 					visibility: ps.visibility,
diff --git a/packages/backend/src/server/api/mastodon/timelineArgs.ts b/packages/backend/src/server/api/mastodon/timelineArgs.ts
index 3fba8ec57a..167d493ab6 100644
--- a/packages/backend/src/server/api/mastodon/timelineArgs.ts
+++ b/packages/backend/src/server/api/mastodon/timelineArgs.ts
@@ -22,12 +22,12 @@ export interface TimelineArgs {
 
 // Values taken from https://docs.joinmastodon.org/client/intro/#boolean
 export function toBoolean(value: string | undefined): boolean | undefined {
-	if (value === undefined) return undefined;
+	if (!value) return undefined;
 	return !['0', 'f', 'F', 'false', 'FALSE', 'off', 'OFF'].includes(value);
 }
 
 export function toInt(value: string | undefined): number | undefined {
-	if (value === undefined) return undefined;
+	if (!value) return undefined;
 	return parseInt(value);
 }
 
diff --git a/packages/megalodon/src/misskey.ts b/packages/megalodon/src/misskey.ts
index 7e493d8fb7..01d5652650 100644
--- a/packages/megalodon/src/misskey.ts
+++ b/packages/megalodon/src/misskey.ts
@@ -1119,7 +1119,7 @@ export default class Misskey implements MegalodonInterface {
       }
       if (options.sensitive) {
         params = Object.assign(params, {
-          cw: ''
+          cw: ' '
         })
       }
       if (options.spoiler_text) {
@@ -1198,7 +1198,7 @@ export default class Misskey implements MegalodonInterface {
       }
       if (_options.sensitive) {
         params = Object.assign(params, {
-          cw: ''
+          cw: ' '
         })
       }
       if (_options.spoiler_text) {
diff --git a/packages/shared/eslint.config.js b/packages/shared/eslint.config.js
index 860eb4a8e8..be7a031b63 100644
--- a/packages/shared/eslint.config.js
+++ b/packages/shared/eslint.config.js
@@ -37,6 +37,10 @@ export default [
 			'no-restricted-imports': ['error', {
 				paths: [{ name: 'punycode' }],
 			}],
+			// https://typescript-eslint.io/rules/prefer-nullish-coalescing/
+			'@typescript-eslint/prefer-nullish-coalescing': ['warn', {
+				ignorePrimitives: true,
+			}],
 		},
 	},
 ];