diff --git a/packages/backend/migration/1663399074403-resize-comments-drive-file.js b/packages/backend/migration/1663399074403-resize-comments-drive-file.js
new file mode 100644
index 000000000..a037f1655
--- /dev/null
+++ b/packages/backend/migration/1663399074403-resize-comments-drive-file.js
@@ -0,0 +1,14 @@
+
+export class resizeCommentsDriveFile1663399074403 {
+    constructor() {
+      this.name = 'resizeCommentsDriveFile1663399074403';
+    }
+
+    async up(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "drive_file" ALTER COLUMN "comment" TYPE character varying(2048)`);
+    }
+
+    async down(queryRunner) {
+        await queryRunner.query(`ALTER TABLE "drive_file" ALTER COLUMN "comment" TYPE character varying(512)`);
+    }
+}
diff --git a/packages/backend/src/server/api/endpoints/drive/files/update.ts b/packages/backend/src/server/api/endpoints/drive/files/update.ts
index e6922cfaa..dedec03e2 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/update.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/update.ts
@@ -52,7 +52,7 @@ export const paramDef = {
 		folderId: { type: 'string', format: 'misskey:id', nullable: true },
 		name: { type: 'string' },
 		isSensitive: { type: 'boolean' },
-		comment: { type: 'string', nullable: true, maxLength: 512 },
+		comment: { type: 'string', nullable: true, maxLength: 2048 },
 	},
 	required: ['fileId'],
 } as const;
diff --git a/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts b/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts
index 56f9ccbae..db2911456 100644
--- a/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts
+++ b/packages/backend/src/server/api/endpoints/drive/files/upload-from-url.ts
@@ -25,7 +25,7 @@ export const paramDef = {
 		url: { type: 'string' },
 		folderId: { type: 'string', format: 'misskey:id', nullable: true, default: null },
 		isSensitive: { type: 'boolean', default: false },
-		comment: { type: 'string', nullable: true, maxLength: 512, default: null },
+		comment: { type: 'string', nullable: true, maxLength: 2048, default: null },
 		marker: { type: 'string', nullable: true, default: null },
 		force: { type: 'boolean', default: false },
 	},
diff --git a/packages/client/src/components/media-caption.vue b/packages/client/src/components/media-caption.vue
index 6cb618b3a..bb87d7ca1 100644
--- a/packages/client/src/components/media-caption.vue
+++ b/packages/client/src/components/media-caption.vue
@@ -104,8 +104,8 @@ function onInputKeydown(evt: KeyboardEvent): void {
 }
 
 const remainingLength = computed((): number => {
-	if (typeof inputValue !== 'string') return 512;
-	return 512 - length(inputValue);
+	if (typeof inputValue !== 'string') return 2048;
+	return 2048 - length(inputValue);
 });
 
 onMounted(() => {