diff --git a/api/s5/s5.go b/api/s5/s5.go
index 85224a5..b469f05 100644
--- a/api/s5/s5.go
+++ b/api/s5/s5.go
@@ -212,7 +212,9 @@ func BuildS5TusApi(identity ed25519.PrivateKey, accounts *account.AccountService
 				"Tus-Resumable",
 				"Tus-Extension",
 				"Tus-Max-Size",
-				"X-HTTP-Method-Override"},
+				"X-HTTP-Method-Override",
+				"Upload-Concat",
+			},
 			AllowCredentials: true,
 		})