diff --git a/backend/internal/middleware/head_middleware.go b/backend/internal/middleware/head_middleware.go
index 541927f6..291d336c 100644
--- a/backend/internal/middleware/head_middleware.go
+++ b/backend/internal/middleware/head_middleware.go
@@ -16,7 +16,7 @@ type headWriter struct {
 
 func (w *headWriter) Write(b []byte) (int, error) {
 	w.size += len(b)
-	return w.size, nil
+	return len(b), nil
 }
 
 func HeadMiddleware() gin.HandlerFunc {