diff --git a/docker2fl/src/docker2fl.rs b/docker2fl/src/docker2fl.rs
index 2a2e540..7514dda 100644
--- a/docker2fl/src/docker2fl.rs
+++ b/docker2fl/src/docker2fl.rs
@@ -106,7 +106,7 @@ impl DockerImageToFlist {
         Ok(())
     }
 
-    pub async fn pack<S: Store>(&mut self, store: S, sender: Option<Sender<i32>>) -> Result<()> {
+    pub async fn pack<S: Store>(&mut self, store: S, sender: Option<Sender<u32>>) -> Result<()> {
         rfs::pack(
             self.meta.clone(),
             store,
@@ -121,7 +121,7 @@ impl DockerImageToFlist {
         Ok(())
     }
 
-    pub async fn convert<S: Store>(&mut self, store: S, sender: Option<Sender<i32>>) -> Result<()> {
+    pub async fn convert<S: Store>(&mut self, store: S, sender: Option<Sender<u32>>) -> Result<()> {
         self.prepare().await?;
         self.pack(store, sender).await?;
 
diff --git a/fl-server/src/handlers.rs b/fl-server/src/handlers.rs
index 5cdc039..d067188 100644
--- a/fl-server/src/handlers.rs
+++ b/fl-server/src/handlers.rs
@@ -176,7 +176,8 @@ pub async fn create_flist_handler(
             );
 
         let container_name = Uuid::new_v4().to_string();
-        let docker_tmp_dir = tempdir::TempDir::new(&container_name).unwrap();
+        let docker_tmp_dir =
+            tempdir::TempDir::new(&container_name).expect("failed to create tmp dir for docker");
         let docker_tmp_dir_path = docker_tmp_dir.path().to_owned();
 
         let (tx, rx) = mpsc::channel();
@@ -193,7 +194,7 @@ pub async fn create_flist_handler(
             state
                 .jobs_state
                 .lock()
-                .unwrap()
+                .expect("failed to lock state")
                 .insert(job.id.clone(), FlistState::Failed);
             return;
         }
@@ -206,10 +207,10 @@ pub async fn create_flist_handler(
             let mut progress: f32 = 0.0;
 
             for _ in 0..files_count - 1 {
-                let step = rx.recv().unwrap() as f32;
+                let step = rx.recv().expect("failed to receive progress") as f32;
                 progress += step;
                 let progress_percentage = progress / files_count as f32 * 100.0;
-                st.jobs_state.lock().unwrap().insert(
+                st.jobs_state.lock().expect("failed to lock state").insert(
                     job_id.clone(),
                     FlistState::InProgress(FlistStateInfo {
                         msg: "flist is in progress".to_string(),
@@ -218,7 +219,7 @@ pub async fn create_flist_handler(
                 );
                 st.flists_progress
                     .lock()
-                    .unwrap()
+                    .expect("failed to lock state")
                     .insert(cloned_fl_path.clone(), progress_percentage);
             }
         });
@@ -248,7 +249,11 @@ pub async fn create_flist_handler(
                     flist_download_url
                 )),
             );
-        state.flists_progress.lock().unwrap().insert(fl_path, 100.0);
+        state
+            .flists_progress
+            .lock()
+            .expect("failed to lock state")
+            .insert(fl_path, 100.0);
     });
 
     Ok(ResponseResult::FlistCreated(current_job))
diff --git a/fl-server/src/serve_flists.rs b/fl-server/src/serve_flists.rs
index 4bbe313..0285421 100644
--- a/fl-server/src/serve_flists.rs
+++ b/fl-server/src/serve_flists.rs
@@ -103,7 +103,7 @@ pub async fn visit_dir_one_level<P: AsRef<std::path::Path>>(
             match state
                 .flists_progress
                 .lock()
-                .unwrap()
+                .expect("failed to lock state")
                 .get(&path.join(&name).to_path_buf())
             {
                 Some(p) => progress = *p,
@@ -113,7 +113,7 @@ pub async fn visit_dir_one_level<P: AsRef<std::path::Path>>(
             let ext = child
                 .path()
                 .extension()
-                .unwrap()
+                .expect("failed to get path extension")
                 .to_string_lossy()
                 .to_string();
             if ext != "fl" {
diff --git a/rfs/src/pack.rs b/rfs/src/pack.rs
index fa76a43..33b2a1b 100644
--- a/rfs/src/pack.rs
+++ b/rfs/src/pack.rs
@@ -27,7 +27,7 @@ pub async fn pack<P: Into<PathBuf>, S: Store>(
     store: S,
     root: P,
     strip_password: bool,
-    sender: Option<Sender<i32>>,
+    sender: Option<Sender<u32>>,
 ) -> Result<()> {
     use tokio::fs;
 
@@ -72,13 +72,13 @@ pub async fn pack<P: Into<PathBuf>, S: Store>(
         &writer,
         &mut pool,
         Item(0, root, OsString::from("/"), meta),
-        sender.clone(),
+        sender.as_ref(),
     )
     .await?;
 
     while !list.is_empty() {
         let dir = list.pop_back().unwrap();
-        pack_one(&mut list, &writer, &mut pool, dir, sender.clone()).await?;
+        pack_one(&mut list, &writer, &mut pool, dir, sender.as_ref()).await?;
     }
 
     pool.close().await;
@@ -105,7 +105,7 @@ async fn pack_one<S: Store>(
     writer: &Writer,
     pool: &mut WorkerPool<Uploader<S>>,
     Item(parent, path, name, meta): Item,
-    sender: Option<Sender<i32>>,
+    sender: Option<&Sender<u32>>,
 ) -> Result<()> {
     use std::os::unix::fs::MetadataExt;
     use tokio::fs;
@@ -139,12 +139,8 @@ async fn pack_one<S: Store>(
         let meta = child.metadata().await?;
         let child_path = path.join(&name);
 
-        if sender.is_some() {
-            sender
-                .clone()
-                .unwrap()
-                .send(1)
-                .context("failed to send progress")?;
+        if let Some(ref sender) = sender {
+            sender.send(1).context("failed to send progress")?;
         }
 
         // if this child a directory we add to the tail of the list