diff --git a/src/keypair.rs b/src/keypair.rs
index aa0a186..b40bdb0 100644
--- a/src/keypair.rs
+++ b/src/keypair.rs
@@ -509,7 +509,7 @@ mod tests {
             message,
             state: client,
         } = ClientRegistration::<Default>::start(&mut OsRng, PASSWORD.as_bytes())?;
-        let ServerRegistrationStartResult { message } =
+        let ServerRegistrationStartResult { message, .. } =
             ServerRegistration::start(&server_setup, message, &[])?;
         let ClientRegistrationFinishResult { message, .. } = client.finish(
             &mut OsRng,
diff --git a/src/opaque.rs b/src/opaque.rs
index 553bf05..bd58479 100644
--- a/src/opaque.rs
+++ b/src/opaque.rs
@@ -357,6 +357,9 @@ impl<CS: CipherSuite> ClientRegistration<CS> {
 pub struct ServerRegistrationStartResult<CS: CipherSuite> {
     /// The registration resposne message to send to the client
     pub message: RegistrationResponse<CS>,
+    /// OPRF key, only used in tests
+    #[cfg(test)]
+    pub oprf_key: GenericArray<u8, <CS::Group as Group>::ScalarLen>,
 }
 
 // Cannot be derived because it would require for CS to be Clone.
@@ -364,6 +367,8 @@ impl<CS: CipherSuite> Clone for ServerRegistrationStartResult<CS> {
     fn clone(&self) -> Self {
         Self {
             message: self.message.clone(),
+            #[cfg(test)]
+            oprf_key: self.oprf_key.clone(),
         }
     }
 }
@@ -417,6 +422,8 @@ impl<CS: CipherSuite> ServerRegistration<CS> {
                 beta,
                 server_s_pk: server_setup.keypair.public().clone(),
             },
+            #[cfg(test)]
+            oprf_key: CS::Group::scalar_as_bytes(oprf_key),
         })
     }
 
@@ -758,6 +765,9 @@ pub struct ServerLoginStartResult<CS: CipherSuite> {
     /// Server MAC key, only used in tests
     #[cfg(test)]
     pub server_mac_key: GenericArray<u8, <CS::Hash as Digest>::OutputSize>,
+    /// OPRF key, only used in tests
+    #[cfg(test)]
+    pub oprf_key: GenericArray<u8, <CS::Group as Group>::ScalarLen>,
 }
 
 // Cannot be derived because it would require for CS to be Clone.
@@ -770,6 +780,8 @@ impl<CS: CipherSuite> Clone for ServerLoginStartResult<CS> {
             handshake_secret: self.handshake_secret.clone(),
             #[cfg(test)]
             server_mac_key: self.server_mac_key.clone(),
+            #[cfg(test)]
+            oprf_key: self.oprf_key.clone(),
         }
     }
 }
@@ -899,6 +911,8 @@ impl<CS: CipherSuite> ServerLogin<CS> {
             handshake_secret: result.2,
             #[cfg(test)]
             server_mac_key: result.3,
+            #[cfg(test)]
+            oprf_key: CS::Group::scalar_as_bytes(oprf_key),
         })
     }
 
diff --git a/src/tests/opaque_test_vectors.rs b/src/tests/opaque_test_vectors.rs
index 14bea14..e4f6aba 100644
--- a/src/tests/opaque_test_vectors.rs
+++ b/src/tests/opaque_test_vectors.rs
@@ -68,6 +68,7 @@ pub struct TestVectorParameters {
     pub handshake_secret: Vec<u8>,
     pub server_mac_key: Vec<u8>,
     pub client_mac_key: Vec<u8>,
+    pub oprf_key: Vec<u8>,
 }
 
 // Pulled from "OPAQUE-3DH Test Vector 1" and "OPAQUE-3DH Test Vector 6"
@@ -492,6 +493,7 @@ fn populate_test_vectors(values: &Value) -> TestVectorParameters {
         handshake_secret: parse!(values, "handshake_secret"),
         server_mac_key: parse!(values, "server_mac_key"),
         client_mac_key: parse!(values, "client_mac_key"),
+        oprf_key: parse!(values, "oprf_key"),
     }
 }
 
@@ -549,6 +551,10 @@ fn test_registration_response() -> Result<(), ProtocolError> {
                 RegistrationRequest::deserialize(&parameters.registration_request[..]).unwrap(),
                 &parameters.credential_identifier,
             )?;
+        assert_eq!(
+            hex::encode(parameters.oprf_key),
+            hex::encode(server_registration_start_result.oprf_key)
+        );
         assert_eq!(
             hex::encode(parameters.registration_response),
             hex::encode(server_registration_start_result.message.serialize())
@@ -667,6 +673,10 @@ fn test_ke2() -> Result<(), ProtocolError> {
             hex::encode(&parameters.server_mac_key),
             hex::encode(server_login_start_result.server_mac_key)
         );
+        assert_eq!(
+            hex::encode(&parameters.oprf_key),
+            hex::encode(server_login_start_result.oprf_key)
+        );
         assert_eq!(
             hex::encode(&parameters.KE2),
             hex::encode(server_login_start_result.message.serialize())