diff --git a/shared/comm-opaque2/src/client/login.rs b/shared/comm-opaque2/src/client/login.rs
--- a/shared/comm-opaque2/src/client/login.rs
+++ b/shared/comm-opaque2/src/client/login.rs
@@ -45,11 +45,8 @@
     let password = self
       .password
       .take()
-      .ok_or_else(|| ProtocolError::InvalidLoginError)?;
-    let state = self
-      .state
-      .take()
-      .ok_or_else(|| ProtocolError::InvalidLoginError)?;
+      .ok_or(ProtocolError::InvalidLoginError)?;
+    let state = self.state.take().ok_or(ProtocolError::InvalidLoginError)?;
     let result = state.finish(
       password.as_bytes(),
       response,
@@ -70,3 +67,9 @@
     }
   }
 }
+
+impl Default for Login {
+  fn default() -> Self {
+    Self::new()
+  }
+}
diff --git a/shared/comm-opaque2/src/client/register.rs b/shared/comm-opaque2/src/client/register.rs
--- a/shared/comm-opaque2/src/client/register.rs
+++ b/shared/comm-opaque2/src/client/register.rs
@@ -39,10 +39,7 @@
     response_payload: &[u8],
   ) -> Result<Vec<u8>, OpaqueError> {
     let response = RegistrationResponse::deserialize(response_payload)?;
-    let state = self
-      .state
-      .take()
-      .ok_or_else(|| ProtocolError::InvalidLoginError)?;
+    let state = self.state.take().ok_or(ProtocolError::InvalidLoginError)?;
     let result = state.finish(
       &mut self.rng,
       password.as_bytes(),
@@ -55,3 +52,9 @@
     Ok(result.message.serialize().to_vec())
   }
 }
+
+impl Default for Registration {
+  fn default() -> Self {
+    Self::new()
+  }
+}
diff --git a/shared/comm-opaque2/src/error.rs b/shared/comm-opaque2/src/error.rs
--- a/shared/comm-opaque2/src/error.rs
+++ b/shared/comm-opaque2/src/error.rs
@@ -8,15 +8,15 @@
 #[derive(Debug)]
 pub struct OpaqueError(ProtocolError);
 
-impl Into<JsValue> for OpaqueError {
-  fn into(self) -> JsValue {
-    JsValue::from(protocol_error_to_js_error(self.0))
+impl From<OpaqueError> for JsValue {
+  fn from(value: OpaqueError) -> Self {
+    Self::from(protocol_error_to_js_error(value.0))
   }
 }
 
-impl Into<ProtocolError> for OpaqueError {
-  fn into(self) -> ProtocolError {
-    self.0
+impl From<OpaqueError> for ProtocolError {
+  fn from(value: OpaqueError) -> Self {
+    value.0
   }
 }
 
diff --git a/shared/comm-opaque2/src/lib.rs b/shared/comm-opaque2/src/lib.rs
--- a/shared/comm-opaque2/src/lib.rs
+++ b/shared/comm-opaque2/src/lib.rs
@@ -22,7 +22,7 @@
   let mut client_register = client::Registration::new();
   let client_message = client_register.start(pass).unwrap();
 
-  let mut server_register = server::Registration::new();
+  let server_register = server::Registration::new();
   let server_response = server_register
     .start(&server_setup, &client_message, username.as_bytes())
     .unwrap();
diff --git a/shared/comm-opaque2/src/server/login.rs b/shared/comm-opaque2/src/server/login.rs
--- a/shared/comm-opaque2/src/server/login.rs
+++ b/shared/comm-opaque2/src/server/login.rs
@@ -55,12 +55,15 @@
     let finalization_payload =
       CredentialFinalization::deserialize(response_payload)?;
 
-    let state = self
-      .state
-      .take()
-      .ok_or_else(|| ProtocolError::InvalidLoginError)?;
+    let state = self.state.take().ok_or(ProtocolError::InvalidLoginError)?;
     let result = state.finish(finalization_payload)?;
     self.session_key = Some(result.session_key.to_vec());
     Ok(())
   }
 }
+
+impl Default for Login {
+  fn default() -> Self {
+    Self::new()
+  }
+}
diff --git a/shared/comm-opaque2/src/server/register.rs b/shared/comm-opaque2/src/server/register.rs
--- a/shared/comm-opaque2/src/server/register.rs
+++ b/shared/comm-opaque2/src/server/register.rs
@@ -38,3 +38,9 @@
     )
   }
 }
+
+impl Default for Registration {
+  fn default() -> Self {
+    Self::new()
+  }
+}