diff --git a/branch/src/main/scala/dev/wishingtree/branch/spider/server/ContextHandler.scala b/branch/src/main/scala/dev/wishingtree/branch/spider/server/ContextHandler.scala
index 28724f8..ecbc79c 100644
--- a/branch/src/main/scala/dev/wishingtree/branch/spider/server/ContextHandler.scala
+++ b/branch/src/main/scala/dev/wishingtree/branch/spider/server/ContextHandler.scala
@@ -30,6 +30,12 @@ trait ContextHandler(val path: String) {
     RequestHandler[?, ?]
   ]
 
+  /** A default handler for requests that are not found. Override this to
+    * provide a custom 404 handler.
+    */
+  val notFoundRequestHandler: RequestHandler[?, ?] =
+    RequestHandler.notFoundHandler
+
   private[spider] inline def httpHandler: HttpHandler = {
     (exchange: HttpExchange) =>
       {
@@ -42,7 +48,7 @@ trait ContextHandler(val path: String) {
               )
               .filter(contextRouter.isDefinedAt)
               .map(contextRouter)
-              .getOrElse(RequestHandler.unimplementedHandler)
+              .getOrElse(notFoundRequestHandler)
           }
           .flatMap(_.lzyRun(exchange))
           .recover { e =>
diff --git a/branch/src/main/scala/dev/wishingtree/branch/spider/server/RequestHandler.scala b/branch/src/main/scala/dev/wishingtree/branch/spider/server/RequestHandler.scala
index a42440c..fbe895c 100644
--- a/branch/src/main/scala/dev/wishingtree/branch/spider/server/RequestHandler.scala
+++ b/branch/src/main/scala/dev/wishingtree/branch/spider/server/RequestHandler.scala
@@ -88,4 +88,10 @@ object RequestHandler {
         throw new Exception("Not implemented")
     }
 
+  private[spider] val notFoundHandler: RequestHandler[Unit, String] =
+    new RequestHandler[Unit, String] {
+      override def handle(request: Request[Unit]): Response[String] =
+        Response(404, "Not found")
+    }
+
 }