diff --git a/docs/downgrade.sql b/docs/downgrade.sql
index 0b6f25e08c..77dea27573 100644
--- a/docs/downgrade.sql
+++ b/docs/downgrade.sql
@@ -1,6 +1,7 @@
 BEGIN;
 
 DELETE FROM "migrations" WHERE name IN (
+    'ConvertCwVarcharToText1713225866247',
     'FixChatFileConstraint1712855579316',
     'DropTimeZone1712425488543',
     'ExpandNoteEdit1711936358554',
@@ -22,6 +23,11 @@ DELETE FROM "migrations" WHERE name IN (
     'RemoveNativeUtilsMigration1705877093218'
 );
 
+--convert-cw-varchar-to-text
+DROP INDEX "IDX_8e3bbbeb3df04d1a8105da4c8f";
+ALTER TABLE "note" ALTER COLUMN "cw" TYPE character varying(512);
+CREATE INDEX "IDX_8e3bbbeb3df04d1a8105da4c8f" ON "note" USING "pgroonga" ("cw" pgroonga_varchar_full_text_search_ops_v2);
+
 -- fix-chat-file-constraint
 ALTER TABLE "messaging_message" DROP CONSTRAINT "FK_535def119223ac05ad3fa9ef64b";
 ALTER TABLE "messaging_message" ADD CONSTRAINT "FK_535def119223ac05ad3fa9ef64b" FOREIGN KEY ("fileId") REFERENCES "drive_file"("id") ON DELETE CASCADE ON UPDATE NO ACTION;
diff --git a/packages/backend-rs/src/model/entity/note.rs b/packages/backend-rs/src/model/entity/note.rs
index cb82f3d94a..5903216c1a 100644
--- a/packages/backend-rs/src/model/entity/note.rs
+++ b/packages/backend-rs/src/model/entity/note.rs
@@ -21,6 +21,7 @@ pub struct Model {
     #[sea_orm(column_type = "Text", nullable)]
     pub text: Option<String>,
     pub name: Option<String>,
+    #[sea_orm(column_type = "Text", nullable)]
     pub cw: Option<String>,
     #[sea_orm(column_name = "userId")]
     pub user_id: String,
diff --git a/packages/backend/src/migration/1713225866247-convert-cw-varchar-to-text.ts b/packages/backend/src/migration/1713225866247-convert-cw-varchar-to-text.ts
new file mode 100644
index 0000000000..93c87a98a8
--- /dev/null
+++ b/packages/backend/src/migration/1713225866247-convert-cw-varchar-to-text.ts
@@ -0,0 +1,21 @@
+import type { MigrationInterface, QueryRunner } from "typeorm";
+
+export class ConvertCwVarcharToText1713225866247 implements MigrationInterface {
+	public async up(queryRunner: QueryRunner): Promise<void> {
+		queryRunner.query(`DROP INDEX "IDX_8e3bbbeb3df04d1a8105da4c8f"`);
+		queryRunner.query(`ALTER TABLE "note" ALTER COLUMN "cw" TYPE text`);
+		queryRunner.query(
+			`CREATE INDEX "IDX_8e3bbbeb3df04d1a8105da4c8f" ON "note" USING "pgroonga" ("cw")`,
+		);
+	}
+
+	public async down(queryRunner: QueryRunner): Promise<void> {
+		queryRunner.query(`DROP INDEX "IDX_8e3bbbeb3df04d1a8105da4c8f"`);
+		queryRunner.query(
+			`ALTER TABLE "note" ALTER COLUMN "cw" TYPE character varying(512)`,
+		);
+		queryRunner.query(
+			`CREATE INDEX "IDX_8e3bbbeb3df04d1a8105da4c8f" ON "note" USING "pgroonga" ("cw" pgroonga_varchar_full_text_search_ops_v2)`,
+		);
+	}
+}
diff --git a/packages/backend/src/models/entities/note.ts b/packages/backend/src/models/entities/note.ts
index 738e43d442..94cd8c7b66 100644
--- a/packages/backend/src/models/entities/note.ts
+++ b/packages/backend/src/models/entities/note.ts
@@ -72,9 +72,8 @@ export class Note {
 	})
 	public name: string | null;
 
-	@Index() // USING pgroonga pgroonga_varchar_full_text_search_ops_v2
-	@Column("varchar", {
-		length: 512,
+	@Index() // USING pgroonga
+	@Column("text", {
 		nullable: true,
 	})
 	public cw: string | null;
diff --git a/packages/backend/src/server/api/endpoints/notes/create.ts b/packages/backend/src/server/api/endpoints/notes/create.ts
index 270c33abd0..c2302f4c8d 100644
--- a/packages/backend/src/server/api/endpoints/notes/create.ts
+++ b/packages/backend/src/server/api/endpoints/notes/create.ts
@@ -114,7 +114,7 @@ export const paramDef = {
 			enum: Object.keys(langmap),
 			nullable: true,
 		},
-		cw: { type: "string", nullable: true, maxLength: 100 },
+		cw: { type: "string", nullable: true, maxLength: MAX_NOTE_TEXT_LENGTH },
 		localOnly: { type: "boolean", default: false },
 		noExtractMentions: { type: "boolean", default: false },
 		noExtractHashtags: { type: "boolean", default: false },