diff --git a/staging/vhost-device-sound/src/audio_backends/pipewire.rs b/staging/vhost-device-sound/src/audio_backends/pipewire.rs
index f48d0db..09572a1 100644
--- a/staging/vhost-device-sound/src/audio_backends/pipewire.rs
+++ b/staging/vhost-device-sound/src/audio_backends/pipewire.rs
@@ -139,21 +139,22 @@ impl AudioBackend for PwBackend {
         {
             let stream_clone = self.stream_params.clone();
             let mut stream_params = stream_clone.write().unwrap();
-            let st = stream_params
-                .get_mut(stream_id as usize)
-                .expect("Stream does not exist");
-            if let Err(err) = st.state.set_parameters() {
-                log::error!("Stream {} set_parameters {}", stream_id, err);
-                msg.code = VIRTIO_SND_S_BAD_MSG;
-            } else if !st.supports_format(request.format) || !st.supports_rate(request.rate) {
-                msg.code = VIRTIO_SND_S_NOT_SUPP;
+            if let Some(st) = stream_params.get_mut(stream_id as usize) {
+                if let Err(err) = st.state.set_parameters() {
+                    log::error!("Stream {} set_parameters {}", stream_id, err);
+                    msg.code = VIRTIO_SND_S_BAD_MSG;
+                } else if !st.supports_format(request.format) || !st.supports_rate(request.rate) {
+                    msg.code = VIRTIO_SND_S_NOT_SUPP;
+                } else {
+                    st.params.features = request.features;
+                    st.params.buffer_bytes = request.buffer_bytes;
+                    st.params.period_bytes = request.period_bytes;
+                    st.params.channels = request.channels;
+                    st.params.format = request.format;
+                    st.params.rate = request.rate;
+                }
             } else {
-                st.params.features = request.features;
-                st.params.buffer_bytes = request.buffer_bytes;
-                st.params.period_bytes = request.period_bytes;
-                st.params.channels = request.channels;
-                st.params.format = request.format;
-                st.params.rate = request.rate;
+                msg.code = VIRTIO_SND_S_BAD_MSG;
             }
         }
         drop(msg);
@@ -163,7 +164,12 @@ impl AudioBackend for PwBackend {
 
     fn prepare(&self, stream_id: u32) -> Result<()> {
         debug!("pipewire prepare");
-        let prepare_result = self.stream_params.write().unwrap()[stream_id as usize]
+        let prepare_result = self
+            .stream_params
+            .write()
+            .unwrap()
+            .get_mut(stream_id as usize)
+            .ok_or_else(|| Error::StreamWithIdNotFound(stream_id))?
             .state
             .prepare();
         if let Err(err) = prepare_result {
@@ -401,69 +407,83 @@ impl AudioBackend for PwBackend {
 
     fn release(&self, stream_id: u32, mut msg: ControlMessage) -> Result<()> {
         debug!("pipewire backend, release function");
-        let release_result = self.stream_params.write().unwrap()[stream_id as usize]
+        let release_result = self
+            .stream_params
+            .write()
+            .unwrap()
+            .get_mut(stream_id as usize)
+            .ok_or_else(|| {
+                msg.code = VIRTIO_SND_S_BAD_MSG;
+                Error::StreamWithIdNotFound(stream_id)
+            })?
             .state
             .release();
         if let Err(err) = release_result {
             log::error!("Stream {} release {}", stream_id, err);
             msg.code = VIRTIO_SND_S_BAD_MSG;
-        } else {
-            let lock_guard = self.thread_loop.lock();
-            let mut stream_hash = self.stream_hash.write().unwrap();
-            let mut stream_listener = self.stream_listener.write().unwrap();
-            let st_buffer = &mut self.stream_params.write().unwrap();
-
-            let Some(stream) = stream_hash.get(&stream_id) else {
-                return Err(Error::StreamWithIdNotFound(stream_id));
-            };
-            stream.disconnect().expect("could not disconnect stream");
-            std::mem::take(&mut st_buffer[stream_id as usize].buffers);
-            stream_hash.remove(&stream_id);
-            stream_listener.remove(&stream_id);
-
-            lock_guard.unlock();
+            return Ok(());
         }
-
+        let lock_guard = self.thread_loop.lock();
+        let mut stream_hash = self.stream_hash.write().unwrap();
+        let mut stream_listener = self.stream_listener.write().unwrap();
+        let st_buffer = &mut self.stream_params.write().unwrap();
+        let stream = stream_hash
+            .get(&stream_id)
+            .expect("Could not find stream with this id in `stream_hash`.");
+        stream.disconnect().expect("could not disconnect stream");
+        std::mem::take(&mut st_buffer[stream_id as usize].buffers);
+        stream_hash.remove(&stream_id);
+        stream_listener.remove(&stream_id);
+        lock_guard.unlock();
         Ok(())
     }
 
     fn start(&self, stream_id: u32) -> Result<()> {
         debug!("pipewire start");
-        let start_result = self.stream_params.write().unwrap()[stream_id as usize]
+        let start_result = self
+            .stream_params
+            .write()
+            .unwrap()
+            .get_mut(stream_id as usize)
+            .ok_or_else(|| Error::StreamWithIdNotFound(stream_id))?
             .state
             .start();
         if let Err(err) = start_result {
             // log the error and continue
             log::error!("Stream {} start {}", stream_id, err);
-        } else {
-            let lock_guard = self.thread_loop.lock();
-            let stream_hash = self.stream_hash.read().unwrap();
-            let Some(stream) = stream_hash.get(&stream_id) else {
-                return Err(Error::StreamWithIdNotFound(stream_id));
-            };
-            stream.set_active(true).expect("could not start stream");
-            lock_guard.unlock();
+            return Ok(());
         }
+        let lock_guard = self.thread_loop.lock();
+        let stream_hash = self.stream_hash.read().unwrap();
+        let stream = stream_hash
+            .get(&stream_id)
+            .expect("Could not find stream with this id in `stream_hash`.");
+        stream.set_active(true).expect("could not start stream");
+        lock_guard.unlock();
         Ok(())
     }
 
     fn stop(&self, stream_id: u32) -> Result<()> {
         debug!("pipewire stop");
-        let stop_result = self.stream_params.write().unwrap()[stream_id as usize]
+        let stop_result = self
+            .stream_params
+            .write()
+            .unwrap()
+            .get_mut(stream_id as usize)
+            .ok_or_else(|| Error::StreamWithIdNotFound(stream_id))?
             .state
             .stop();
         if let Err(err) = stop_result {
             log::error!("Stream {} stop {}", stream_id, err);
-        } else {
-            let lock_guard = self.thread_loop.lock();
-            let stream_hash = self.stream_hash.read().unwrap();
-            let Some(stream) = stream_hash.get(&stream_id) else {
-                return Err(Error::StreamWithIdNotFound(stream_id));
-            };
-            stream.set_active(false).expect("could not stop stream");
-            lock_guard.unlock();
+            return Ok(());
         }
-
+        let lock_guard = self.thread_loop.lock();
+        let stream_hash = self.stream_hash.read().unwrap();
+        let stream = stream_hash
+            .get(&stream_id)
+            .expect("Could not find stream with this id in `stream_hash`.");
+        stream.set_active(false).expect("could not stop stream");
+        lock_guard.unlock();
         Ok(())
     }
 }