diff --git a/pkgs/development/python-modules/trezor/default.nix b/pkgs/development/python-modules/trezor/default.nix
index cc31939ff03..3a6b5f62e4f 100644
--- a/pkgs/development/python-modules/trezor/default.nix
+++ b/pkgs/development/python-modules/trezor/default.nix
@@ -1,5 +1,5 @@
 { lib, fetchPypi, buildPythonPackage,
-  protobuf, hidapi, ecdsa, mnemonic, requests, pyblake2, click, libusb1
+  protobuf, hidapi, ecdsa, mnemonic, requests, pyblake2, click, libusb1, rlp
 }:
 
 buildPythonPackage rec {
@@ -12,7 +12,7 @@ buildPythonPackage rec {
     sha256 = "a481191011bade98f1e9f1201e7c72a83945050657bbc90dc4ac32dc8b8b46a4";
   };
 
-  propagatedBuildInputs = [ protobuf hidapi ecdsa mnemonic requests pyblake2 click libusb1 ];
+  propagatedBuildInputs = [ protobuf hidapi ecdsa mnemonic requests pyblake2 click libusb1 rlp ];
 
   # There are no actual tests: "ImportError: No module named tests"
   doCheck = false;