diff --git a/proto/src/server/testing/mod.rs b/proto/src/server/testing/mod.rs
new file mode 100644
index 0000000..341eb0f
--- /dev/null
+++ b/proto/src/server/testing/mod.rs
@@ -0,0 +1,12 @@
+//! Testing utilities for server protocol code.
+
+mod server;
+mod user_status;
+
+pub use server::{
+  ClientHandler, ClientHandlerFactory, LogHandler, LogHandlerFactory,
+  RequestHandler, Server, ServerBuilder, ServerHandle, ShutdownType,
+};
+pub use user_status::{
+  UserStatusHandler, UserStatusHandlerFactory, UserStatusMap,
+};
diff --git a/proto/src/server/testing.rs b/proto/src/server/testing/server.rs
similarity index 82%
rename from proto/src/server/testing.rs
rename to proto/src/server/testing/server.rs
index aed1ca1..3b984de 100644
--- a/proto/src/server/testing.rs
+++ b/proto/src/server/testing/server.rs
@@ -1,13 +1,10 @@
 //! Provides utilities for testing protocol code.
 
-use std::collections::HashMap;
 use std::io;
 use std::net::{IpAddr, Ipv4Addr, SocketAddr};
-use std::sync::Arc;
 
 use anyhow::{bail, Context};
 use log::{info, warn};
-use parking_lot::Mutex;
 use tokio::net::tcp::{OwnedReadHalf, OwnedWriteHalf};
 use tokio::net::{TcpListener, TcpStream};
 use tokio::sync::mpsc;
@@ -15,10 +12,7 @@ use tokio::sync::oneshot;
 use tokio::sync::watch;
 
 use crate::core::{FrameReader, FrameWriter, Worker};
-use crate::server::{
-  LoginResponse, ServerRequest, ServerResponse, UserStatusRequest,
-  UserStatusResponse,
-};
+use crate::server::{LoginResponse, ServerRequest, ServerResponse};
 
 /// A handler for a single client connected to the server.
 pub trait ClientHandler: Send {
@@ -374,98 +368,11 @@ impl ClientHandlerFactory for LogHandlerFactory {
   }
 }
 
-// USER STATUS HANDLER
-
-/// A map of user names to user status responses to serve.
-#[derive(Debug, Default)]
-pub struct UserStatusMap {
-  map: HashMap<String, UserStatusResponse>,
-}
-
-// IDEA: impl FromIterator<UserStatusResponse> for UserStatusMap.
-
-impl UserStatusMap {
-  /// Inserts the given `response` in this map.
-  /// Overwrites the previous entry for the same user name, if any.
-  pub fn insert(&mut self, response: UserStatusResponse) {
-    self.map.insert(response.user_name.clone(), response);
-  }
-
-  /// Returns a clone of the response for the given user name.
-  pub fn get(&self, user_name: &str) -> Option<UserStatusResponse> {
-    self.map.get(user_name).map(|response| response.clone())
-  }
-}
-
-/// A handler that can serve responses to user status requests.
-/// Responses are sent only for users who appear in `user_status_map`.
-/// All other requests are ignored.
-#[derive(Clone, Default)]
-pub struct UserStatusHandler {
-  user_status_map: Arc<Mutex<UserStatusMap>>,
-}
-
-impl RequestHandler for UserStatusHandler {
-  fn handle(
-    &mut self,
-    request: &ServerRequest,
-  ) -> anyhow::Result<Option<ServerResponse>> {
-    let user_name = match request {
-      ServerRequest::UserStatusRequest(UserStatusRequest { ref user_name }) => {
-        user_name
-      }
-      _ => {
-        warn!("Unhandled request: {:?}", request);
-        return Ok(None);
-      }
-    };
-
-    let entry = self.user_status_map.lock().get(user_name);
-    if let Some(response) = entry {
-      Ok(Some(ServerResponse::UserStatusResponse(response)))
-    } else {
-      warn!("Received UserStatusRequest for unknown user {}", user_name);
-      Ok(None)
-    }
-  }
-}
-
-/// A factory for `UserStatusHandler`. All handlers share `user_status_map`.
-#[derive(Default)]
-pub struct UserStatusHandlerFactory {
-  /// The status map from which responses are served.
-  ///
-  /// Testing code may wish to retain a copy of this in order to mutate the map
-  /// concurrently with requests being handled.
-  pub user_status_map: Arc<Mutex<UserStatusMap>>,
-}
-
-impl ClientHandlerFactory for UserStatusHandlerFactory {
-  type Handler = UserStatusHandler;
-
-  fn make(&self) -> Self::Handler {
-    Self::Handler {
-      user_status_map: self.user_status_map.clone(),
-    }
-  }
-}
-
-impl UserStatusHandlerFactory {
-  /// Convenience function to create a new factory wrapping the given `map`.
-  pub fn new(map: UserStatusMap) -> Self {
-    Self {
-      user_status_map: Arc::new(Mutex::new(map)),
-    }
-  }
-}
-
 #[cfg(test)]
 mod tests {
   use tokio::net::TcpStream;
 
-  use super::{
-    LogHandlerFactory, ServerBuilder, ShutdownType, UserStatusHandlerFactory,
-  };
+  use super::{LogHandlerFactory, ServerBuilder, ShutdownType};
 
   // Enable capturing logs in tests.
   fn init() {
diff --git a/proto/src/server/testing/user_status.rs b/proto/src/server/testing/user_status.rs
new file mode 100644
index 0000000..426738b
--- /dev/null
+++ b/proto/src/server/testing/user_status.rs
@@ -0,0 +1,93 @@
+use std::collections::HashMap;
+use std::sync::Arc;
+
+use log::warn;
+use parking_lot::Mutex;
+
+use crate::server::testing::{ClientHandlerFactory, RequestHandler};
+use crate::server::{
+  ServerRequest, ServerResponse, UserStatusRequest, UserStatusResponse,
+};
+
+/// A map of user names to user status responses to serve.
+#[derive(Debug, Default)]
+pub struct UserStatusMap {
+  map: HashMap<String, UserStatusResponse>,
+}
+
+// IDEA: impl FromIterator<UserStatusResponse> for UserStatusMap.
+
+impl UserStatusMap {
+  /// Inserts the given `response` in this map.
+  /// Overwrites the previous entry for the same user name, if any.
+  pub fn insert(&mut self, response: UserStatusResponse) {
+    self.map.insert(response.user_name.clone(), response);
+  }
+
+  /// Returns a clone of the response for the given user name.
+  pub fn get(&self, user_name: &str) -> Option<UserStatusResponse> {
+    self.map.get(user_name).map(|response| response.clone())
+  }
+}
+
+/// A handler that can serve responses to user status requests.
+/// Responses are sent only for users who appear in `user_status_map`.
+/// All other requests are ignored.
+#[derive(Clone, Default)]
+pub struct UserStatusHandler {
+  user_status_map: Arc<Mutex<UserStatusMap>>,
+}
+
+impl RequestHandler for UserStatusHandler {
+  fn handle(
+    &mut self,
+    request: &ServerRequest,
+  ) -> anyhow::Result<Option<ServerResponse>> {
+    let user_name = match request {
+      ServerRequest::UserStatusRequest(UserStatusRequest { ref user_name }) => {
+        user_name
+      }
+      _ => {
+        warn!("Unhandled request: {:?}", request);
+        return Ok(None);
+      }
+    };
+
+    let entry = self.user_status_map.lock().get(user_name);
+    if let Some(response) = entry {
+      Ok(Some(ServerResponse::UserStatusResponse(response)))
+    } else {
+      warn!("Received UserStatusRequest for unknown user {}", user_name);
+      Ok(None)
+    }
+  }
+}
+
+/// A factory for `UserStatusHandler`. All handlers share `user_status_map`.
+#[derive(Default)]
+pub struct UserStatusHandlerFactory {
+  /// The status map from which responses are served.
+  ///
+  /// Testing code may wish to retain a copy of this in order to mutate the map
+  /// concurrently with requests being handled.
+  pub user_status_map: Arc<Mutex<UserStatusMap>>,
+}
+
+impl ClientHandlerFactory for UserStatusHandlerFactory {
+  type Handler = UserStatusHandler;
+
+  fn make(&self) -> Self::Handler {
+    Self::Handler {
+      user_status_map: self.user_status_map.clone(),
+    }
+  }
+}
+
+impl UserStatusHandlerFactory {
+  /// Convenience function to create a new factory wrapping the given `map`.
+  pub fn new(map: UserStatusMap) -> Self {
+    Self {
+      user_status_map: Arc::new(Mutex::new(map)),
+    }
+  }
+}