diff --git a/backend/internal/web/handlers_files.go b/backend/internal/web/handlers_files.go
index 4e3f9fe..6fd931e 100644
--- a/backend/internal/web/handlers_files.go
+++ b/backend/internal/web/handlers_files.go
@@ -202,10 +202,10 @@ func FileUploadHandler(deps FilesDeps) http.HandlerFunc {
 			slog.Default().Error("files upload: InsertTabloFile failed", "tablo_id", tablo.ID, "s3_key", s3Key, "err", err)
 			// Best-effort S3 cleanup — orphan prevention until Phase 6 reconciler exists.
 			cleanupCtx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
-			defer cancel()
 			if delErr := deps.Files.Delete(cleanupCtx, s3Key); delErr != nil {
 				slog.Default().Error("files upload: S3 cleanup after DB failure", "s3_key", s3Key, "err", delErr)
 			}
+			cancel() // call immediately after Delete, not via defer
 			http.Error(w, "internal server error", http.StatusInternalServerError)
 			return
 		}