diff --git a/src/key_exchange/traits.rs b/src/key_exchange/traits.rs
index 6a78872..e3ed441 100644
--- a/src/key_exchange/traits.rs
+++ b/src/key_exchange/traits.rs
@@ -23,6 +23,7 @@ pub type GenerateKe2Result<K, D, G> = (
     <K as KeyExchange<D, G>>::KE2State,
     <K as KeyExchange<D, G>>::KE2Message,
     Vec<u8>,
+    generic_array::GenericArray<u8, <D as digest::Digest>::OutputSize>,
 );
 #[cfg(not(test))]
 pub type GenerateKe3Result<K, D, G> = (Vec<u8>, <K as KeyExchange<D, G>>::KE3Message);
diff --git a/src/key_exchange/tripledh.rs b/src/key_exchange/tripledh.rs
index 77c1260..274b511 100644
--- a/src/key_exchange/tripledh.rs
+++ b/src/key_exchange/tripledh.rs
@@ -128,6 +128,8 @@ impl<D: Hash, G: Group> KeyExchange<D, G> for TripleDH {
             },
             #[cfg(test)]
             result.3,
+            #[cfg(test)]
+            result.1,
         ))
     }
 
diff --git a/src/opaque.rs b/src/opaque.rs
index bc70714..0cce525 100644
--- a/src/opaque.rs
+++ b/src/opaque.rs
@@ -748,6 +748,8 @@ pub struct ServerLoginStartResult<CS: CipherSuite> {
     /// Handshake secret, only used tests
     #[cfg(test)]
     pub handshake_secret: Vec<u8>,
+    #[cfg(test)]
+    pub server_mac_key: GenericArray<u8, <CS::Hash as Digest>::OutputSize>,
 }
 
 // Cannot be derived because it would require for CS to be Clone.
@@ -758,6 +760,8 @@ impl<CS: CipherSuite> Clone for ServerLoginStartResult<CS> {
             state: self.state.clone(),
             #[cfg(test)]
             handshake_secret: self.handshake_secret.clone(),
+            #[cfg(test)]
+            server_mac_key: self.server_mac_key.clone(),
         }
     }
 }
@@ -885,6 +889,8 @@ impl<CS: CipherSuite> ServerLogin<CS> {
             },
             #[cfg(test)]
             handshake_secret: result.2,
+            #[cfg(test)]
+            server_mac_key: result.3,
         })
     }
 
diff --git a/src/tests/opaque_test_vectors.rs b/src/tests/opaque_test_vectors.rs
index a90e689..c1dcfc9 100644
--- a/src/tests/opaque_test_vectors.rs
+++ b/src/tests/opaque_test_vectors.rs
@@ -66,6 +66,7 @@ pub struct TestVectorParameters {
     pub auth_key: Vec<u8>,
     pub randomized_pwd: Vec<u8>,
     pub handshake_secret: Vec<u8>,
+    pub server_mac_key: Vec<u8>,
 }
 
 // Pulled from "OPAQUE-3DH Test Vector 1" and "OPAQUE-3DH Test Vector 6"
@@ -488,6 +489,7 @@ fn populate_test_vectors(values: &Value) -> TestVectorParameters {
         auth_key: parse!(values, "auth_key"),
         randomized_pwd: parse!(values, "randomized_pwd"),
         handshake_secret: parse!(values, "handshake_secret"),
+        server_mac_key: parse!(values, "server_mac_key"),
     }
 }
 
@@ -659,6 +661,10 @@ fn test_ke2() -> Result<(), ProtocolError> {
             hex::encode(&parameters.handshake_secret),
             hex::encode(server_login_start_result.handshake_secret)
         );
+        assert_eq!(
+            hex::encode(&parameters.server_mac_key),
+            hex::encode(server_login_start_result.server_mac_key)
+        );
         assert_eq!(
             hex::encode(&parameters.KE2),
             hex::encode(server_login_start_result.message.serialize())