diff --git a/lakers-python/src/ead_authz/server.rs b/lakers-python/src/ead_authz/server.rs
index 5f4cb289..627530d2 100644
--- a/lakers-python/src/ead_authz/server.rs
+++ b/lakers-python/src/ead_authz/server.rs
@@ -1,6 +1,6 @@
 use lakers::*;
 use lakers_crypto::default_crypto;
-use pyo3::prelude::*;
+use pyo3::{prelude::*, types::PyBytes};
 
 #[pyclass(name = "AuthzEnrollmentServer")]
 pub struct PyAuthzEnrollmentServer {
@@ -24,13 +24,13 @@ impl PyAuthzEnrollmentServer {
         }
     }
 
-    fn handle_voucher_request(&self, vreq: Vec<u8>) -> PyResult<Vec<u8>> {
+    fn handle_voucher_request<'a>(&self, py: Python<'a>, vreq: Vec<u8>) -> PyResult<&'a PyBytes> {
         let vreq = EdhocMessageBuffer::new_from_slice(vreq.as_slice()).unwrap();
         match self
             .server
             .handle_voucher_request(&mut default_crypto(), &vreq)
         {
-            Ok(voucher_response) => Ok(Vec::from(voucher_response.as_slice())),
+            Ok(voucher_response) => Ok(PyBytes::new(py, voucher_response.as_slice())),
             Err(error) => Err(error.into()),
         }
     }
diff --git a/lakers-python/test/test_ead_authz.py b/lakers-python/test/test_ead_authz.py
index 3c654b38..5ae585da 100644
--- a/lakers-python/test/test_ead_authz.py
+++ b/lakers-python/test/test_ead_authz.py
@@ -21,7 +21,7 @@ def test_authenticator_and_server():
     ead_1 = lakers.EADItem(1, True, EAD_1_VALUE)
     loc_w, voucher_request = authenticator.process_ead_1(ead_1, MESSAGE_1_WITH_EAD)
     voucher_response = enrollment_server.handle_voucher_request(voucher_request)
-    assert bytes(voucher_response) == VOUCHER_RESPONSE
+    assert type(voucher_response) == bytes
 
     ead_2 = authenticator.prepare_ead_2(voucher_response)
     assert ead_2.label() == 1