diff --git a/src/app.rs b/src/app.rs
index ce242f67..4dd31b83 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -436,10 +436,11 @@ where
     }
 }
 
-impl<S, C> WireframeApp<S, C>
+impl<S, C, E> WireframeApp<S, C, E>
 where
-    S: Serializer + crate::frame::FrameMetadata<Frame = Envelope>,
+    S: Serializer + crate::frame::FrameMetadata<Frame = Envelope> + Send + Sync,
     C: Send + 'static,
+    E: Packet,
 {
     /// Try parsing the frame using [`FrameMetadata::parse`], falling back to
     /// full deserialization on failure.
@@ -589,26 +590,12 @@ where
     where
         W: tokio::io::AsyncWrite + Unpin,
     {
+        // Parse the frame first; routing is handled below to avoid duplicating
+        // logic on the success path.
         let (env, _) = match self.parse_envelope(frame) {
-            Ok((env, _)) => {
+            Ok(result) => {
                 *deser_failures = 0;
-                let (id, bytes) = env.into_parts();
-                if let Some(service) = routes.get(&id) {
-                    let request = ServiceRequest::new(bytes);
-                    match service.call(request).await {
-                        Ok(resp) => {
-                            let response = E::from_parts(id, resp.into_inner());
-                            if let Err(e) = self.send_response(stream, &response).await {
-                                log::warn!("failed to send response: {e}");
-                            }
-                        }
-                        Err(e) => {
-                            log::warn!("handler error for id {id}: {e}");
-                        }
-                    }
-                } else {
-                    log::warn!("no handler for message id {id}");
-                }
+                result
             }
             Err(e) => {
                 *deser_failures += 1;
diff --git a/tests/util.rs b/tests/util.rs
index ac27e08e..2ef136c8 100644
--- a/tests/util.rs
+++ b/tests/util.rs
@@ -42,9 +42,14 @@ pub fn processor() -> LengthPrefixedProcessor {
 ///
 /// Returns any I/O errors encountered while interacting with the in-memory
 /// duplex stream.
-pub async fn run_app_with_frame<S>(app: WireframeApp<S>, frame: Vec<u8>) -> io::Result<Vec<u8>>
+pub async fn run_app_with_frame<S, C, E>(
+    app: WireframeApp<S, C, E>,
+    frame: Vec<u8>,
+) -> io::Result<Vec<u8>>
 where
     S: TestSerializer,
+    C: Send + 'static,
+    E: Packet,
 {
     run_app_with_frame_with_capacity(app, frame, DEFAULT_CAPACITY).await
 }
@@ -58,13 +63,15 @@ where
 /// # Panics
 ///
 /// Panics if the spawned task running the application panics.
-pub async fn run_app_with_frame_with_capacity<S>(
-    app: WireframeApp<S>,
+pub async fn run_app_with_frame_with_capacity<S, C, E>(
+    app: WireframeApp<S, C, E>,
     frame: Vec<u8>,
     capacity: usize,
 ) -> io::Result<Vec<u8>>
 where
     S: TestSerializer,
+    C: Send + 'static,
+    E: Packet,
 {
     run_app_with_frames_with_capacity(app, vec![frame], capacity).await
 }
@@ -76,12 +83,14 @@ where
 /// Returns any I/O errors encountered while interacting with the in-memory
 /// duplex stream.
 #[allow(dead_code)]
-pub async fn run_app_with_frames<S>(
-    app: WireframeApp<S>,
+pub async fn run_app_with_frames<S, C, E>(
+    app: WireframeApp<S, C, E>,
     frames: Vec<Vec<u8>>,
 ) -> io::Result<Vec<u8>>
 where
     S: TestSerializer,
+    C: Send + 'static,
+    E: Packet,
 {
     run_app_with_frames_with_capacity(app, frames, DEFAULT_CAPACITY).await
 }
@@ -95,13 +104,15 @@ where
 /// # Panics
 ///
 /// Panics if the spawned task running the application panics.
-pub async fn run_app_with_frames_with_capacity<S>(
-    app: WireframeApp<S>,
+pub async fn run_app_with_frames_with_capacity<S, C, E>(
+    app: WireframeApp<S, C, E>,
     frames: Vec<Vec<u8>>,
     capacity: usize,
 ) -> io::Result<Vec<u8>>
 where
     S: TestSerializer,
+    C: Send + 'static,
+    E: Packet,
 {
     let (mut client, server) = duplex(capacity);
     let server_task = tokio::spawn(async move {