diff --git a/apps/server/src/modules/files-storage/controller/files-storage.controller.ts b/apps/server/src/modules/files-storage/controller/files-storage.controller.ts
index 736d69e3e29..11232f3ebf2 100644
--- a/apps/server/src/modules/files-storage/controller/files-storage.controller.ts
+++ b/apps/server/src/modules/files-storage/controller/files-storage.controller.ts
@@ -135,7 +135,7 @@ export class FilesStorageController {
 		@Req() req: Request,
 		@Res({ passthrough: true }) response: Response,
 		@Headers('Range') bytesRange?: string
-	): Promise<StreamableFile> {
+	): Promise<StreamableFile | void> {
 		const fileResponse = await this.filesStorageUC.downloadPreview(
 			currentUser.userId,
 			params,
@@ -143,6 +143,14 @@ export class FilesStorageController {
 			bytesRange
 		);
 
+		if (req.headers['if-none-match'] === fileResponse.etag) {
+			response.status(304);
+
+			return undefined;
+		}
+
+		response.set({ ETag: fileResponse.etag });
+
 		const streamableFile = this.streamFileToClient(req, fileResponse, response, bytesRange);
 
 		return streamableFile;