diff --git a/dictation_server/src/features/files/types/types.ts b/dictation_server/src/features/files/types/types.ts
index 2de8a4a..2fda838 100644
--- a/dictation_server/src/features/files/types/types.ts
+++ b/dictation_server/src/features/files/types/types.ts
@@ -1,4 +1,6 @@
 import { ApiProperty } from '@nestjs/swagger';
+import { Type } from 'class-transformer';
+import { IsInt, Min } from 'class-validator';
 
 export class AudioUploadLocationRequest {}
 
@@ -23,6 +25,9 @@ export class AudioDownloadLocationResponse {
 
 export class TemplateDownloadLocationRequest {
   @ApiProperty({ description: '文字起こし対象の音声ファイルID' })
+  @Type(() => Number)
+  @Min(0)
+  @IsInt()
   audioFileId: number;
 }