diff --git a/apps/server/src/modules/common-cartridge/service/common-cartridge-export.service.ts b/apps/server/src/modules/common-cartridge/service/common-cartridge-export.service.ts
index 33d9d03dac..6b9d3ce1aa 100644
--- a/apps/server/src/modules/common-cartridge/service/common-cartridge-export.service.ts
+++ b/apps/server/src/modules/common-cartridge/service/common-cartridge-export.service.ts
@@ -226,8 +226,9 @@ export class CommonCartridgeExportService {
 
 	private async findCourseCommonCartridgeMetadata(courseId: string): Promise<CourseCommonCartridgeMetadataDto> {
 		const courseMetadata = await this.coursesClientAdapter.getCourseCommonCartridgeMetadata(courseId);
+		const dto = new CourseCommonCartridgeMetadataDto(courseMetadata);
 
-		return courseMetadata;
+		return dto;
 	}
 
 	private async findRoomBoardByCourseId(courseId: string): Promise<RoomBoardDto> {