diff --git a/src/catalog.rs b/src/catalog.rs
index f9672f2..e7f476b 100644
--- a/src/catalog.rs
+++ b/src/catalog.rs
@@ -184,7 +184,10 @@ pub struct Catalog {
 }
 
 impl Catalog {
-    pub fn populate(&mut self) -> anyhow::Result<()> {
+    pub fn populate_with_progress(
+        &mut self,
+        progress_bar: Option<crate::progress::ProgressBar>,
+    ) -> anyhow::Result<()> {
         let mut new_entries = BTreeMap::new();
         let mut old_entries = Arc::new(std::mem::take(&mut self.entries));
 
@@ -218,14 +221,46 @@ impl Catalog {
                 move |(_, relpath)| !old_entries.contains_key(relpath)
             });
         let metadata = self.metadata.clone();
-        for result in crate::parallel::for_each(iterator, move |res| {
-            res.and_then(|(entry, relative_path)| {
-                checksum_entry(metadata.algo, entry, relative_path)
+
+        let results_iter = if let Some(ref bar) = progress_bar {
+            let discovery_bar = bar.clone();
+            let progress_bar = progress_bar.clone();
+            crate::parallel::for_each_with_discovery_callback(
+                iterator,
+                move |res| {
+                    let result = res.and_then(|(entry, relative_path)| {
+                        checksum_entry(metadata.algo, entry, relative_path)
+                    });
+                    if let Some(ref bar) = progress_bar {
+                        bar.notify_record_processed(result.as_ref().map(|(size, _, _)| *size).ok());
+                    }
+                    result
+                },
+                Some(Box::new(move || {
+                    discovery_bar.notify_file_discovered();
+                })),
+            )
+        } else {
+            crate::parallel::for_each(iterator, move |res| {
+                res.and_then(|(entry, relative_path)| {
+                    checksum_entry(metadata.algo, entry, relative_path)
+                })
             })
-        }) {
-            let (entry, relative_filename, signature) = result?;
+        };
+
+        let results_iter = if let Some(ref bar) = progress_bar {
+            let bar_clone = bar.clone();
+            results_iter.with_total_callback(move |total| {
+                bar_clone.set_length(total);
+            })
+        } else {
+            results_iter
+        };
+
+        for result in results_iter {
+            let (_, relative_filename, signature) = result?;
             let prev = new_entries.insert(relative_filename, signature);
-            assert!(prev.is_none(), "Entry {entry:?} was already in catalog!")
+            assert!(prev.is_none(), "Entry was already in catalog!")
         }
 
         assert!(self.entries.is_empty());
diff --git a/src/main.rs b/src/main.rs
index 3705612..63fee65 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -156,7 +156,7 @@ fn load_and_verify_catalog(
     let catalog_filename = catalog.metadata().signature_file_path().clone();
     let algo = catalog.metadata().algo();
 
-    let bar = crate::progress::ProgressBar::new(catalog.len());
+    let bar = crate::progress::ProgressBar::new(Some(catalog.len()));
 
     let mut report = crate::parallel::for_each(catalog.into_iter(), move |entry| {
         let res = entry
@@ -194,7 +194,9 @@ fn create_catalog(params: SignParams, config: &config::Config) -> anyhow::Result
 
     let mut catalog = directory.empty_catalog(algo);
 
-    catalog.populate()?;
+    let bar = crate::progress::ProgressBar::new(None);
+
+    catalog.populate_with_progress(Some(bar))?;
 
     catalog.write_signature_file(false)
 }
diff --git a/src/parallel.rs b/src/parallel.rs
index 11c68d5..ab56b42 100644
--- a/src/parallel.rs
+++ b/src/parallel.rs
@@ -1,25 +1,46 @@
+use std::sync::Arc;
 use std::thread::JoinHandle;
 
-pub(crate) fn for_each<I, F, R, T>(iterator: I, handler: F) -> impl Iterator<Item = R>
+pub(crate) fn for_each<I, F, R, T>(iterator: I, handler: F) -> ResultsIterator<R>
 where
     I: Iterator<Item = T> + Send + 'static,
     R: Send + 'static,
     F: Fn(T) -> R + Send + Clone + 'static,
     T: Send + 'static,
 {
-    let (entries_sender, entries_receiver) = crossbeam_channel::bounded(num_cpus::get() * 4);
+    for_each_with_discovery_callback(iterator, handler, None)
+}
 
+pub(crate) fn for_each_with_discovery_callback<I, F, R, T>(
+    iterator: I,
+    handler: F,
+    discovery_callback: Option<Box<dyn Fn() + Send + Sync>>,
+) -> ResultsIterator<R>
+where
+    I: Iterator<Item = T> + Send + 'static,
+    R: Send + 'static,
+    F: Fn(T) -> R + Send + Clone + 'static,
+    T: Send + 'static,
+{
+    let (entries_sender, entries_receiver) = crossbeam_channel::unbounded();
     let (results_sender, results_receiver) = crossbeam_channel::unbounded();
+    let (total_sender, total_receiver) = crossbeam_channel::bounded(1);
+
+    let discovery_callback = discovery_callback.map(Arc::new);
 
     let producer = std::thread::spawn(move || {
         let mut size = 0;
         for entry in iterator {
             size += 1;
+            if let Some(ref callback) = discovery_callback {
+                callback();
+            }
             if entries_sender.send(entry).is_err() {
                 log::debug!("Entries sender channel closed. Closing producer");
                 break;
             }
         }
+        let _ = total_sender.send(size);
         size
     });
 
@@ -37,33 +58,51 @@ where
     }
     drop(results_sender);
 
-    ResultsIterator::new(producer, results_receiver)
+    ResultsIterator::new(producer, results_receiver, total_receiver)
 }
 
 pub struct ResultsIterator<R> {
-    join_handle: Option<JoinHandle<usize>>,
     total: Option<usize>,
     receiver: crossbeam_channel::Receiver<R>,
+    total_receiver: crossbeam_channel::Receiver<usize>,
     received: usize,
+    on_total_discovered: Option<Box<dyn FnOnce(usize) + Send>>,
 }
 impl<R> ResultsIterator<R> {
-    fn new(join_handle: JoinHandle<usize>, receiver: crossbeam_channel::Receiver<R>) -> Self {
+    fn new(
+        _join_handle: JoinHandle<usize>,
+        receiver: crossbeam_channel::Receiver<R>,
+        total_receiver: crossbeam_channel::Receiver<usize>,
+    ) -> Self {
         Self {
-            join_handle: Some(join_handle),
             total: None,
             receiver,
+            total_receiver,
             received: 0,
+            on_total_discovered: None,
         }
     }
+
+    pub fn with_total_callback<F>(mut self, callback: F) -> Self
+    where
+        F: FnOnce(usize) + Send + 'static,
+    {
+        self.on_total_discovered = Some(Box::new(callback));
+        self
+    }
 }
 
 impl<R> Iterator for ResultsIterator<R> {
     type Item = R;
 
     fn next(&mut self) -> Option<Self::Item> {
-        if let Some(handle) = self.join_handle.take() {
-            if handle.is_finished() {
-                self.total.replace(handle.join().unwrap());
+        // Check if we received the total count
+        if self.total.is_none() {
+            if let Ok(total) = self.total_receiver.try_recv() {
+                self.total.replace(total);
+                if let Some(callback) = self.on_total_discovered.take() {
+                    callback(total);
+                }
             }
         }
 
@@ -73,8 +112,34 @@ impl<R> Iterator for ResultsIterator<R> {
             }
         }
 
-        // we either didn't finish, or we are still missing our total
-        self.receiver.recv().ok()
+        // Get the next result
+        match self.receiver.recv().ok() {
+            Some(item) => {
+                self.received += 1;
+                // Check again for total after receiving an item
+                if self.total.is_none() {
+                    if let Ok(total) = self.total_receiver.try_recv() {
+                        self.total.replace(total);
+                        if let Some(callback) = self.on_total_discovered.take() {
+                            callback(total);
+                        }
+                    }
+                }
+                Some(item)
+            }
+            None => {
+                // No more results, but check one last time for total
+                if self.total.is_none() {
+                    if let Ok(total) = self.total_receiver.try_recv() {
+                        self.total.replace(total);
+                        if let Some(callback) = self.on_total_discovered.take() {
+                            callback(total);
+                        }
+                    }
+                }
+                None
+            }
+        }
     }
 }
 
diff --git a/src/progress.rs b/src/progress.rs
index b61f698..386145f 100644
--- a/src/progress.rs
+++ b/src/progress.rs
@@ -8,21 +8,38 @@ const SIZE_UPDATE_FREQ: std::time::Duration = std::time::Duration::from_secs(3);
 pub struct ProgressBar {
     bar: Arc<indicatif::ProgressBar>,
     size: Arc<AtomicU64>,
+    discovered_count: Arc<AtomicU64>,
 }
 
 impl ProgressBar {
-    pub fn new(len: usize) -> Self {
-        let bar = indicatif::ProgressBar::new(len.try_into().unwrap());
-        bar.set_draw_target(ProgressDrawTarget::stderr_with_hz(5));
-        bar.set_style(
-            ProgressStyle::with_template(
-                "[{elapsed_precise}] {bar:40.cyan/blue} {pos:>7}/{len:7} {msg}",
-            )
-            .unwrap(),
-        );
+    pub fn new(len: Option<usize>) -> Self {
+        let bar = match len {
+            Some(length) => {
+                let bar = indicatif::ProgressBar::new(length.try_into().unwrap());
+                bar.set_style(
+                    ProgressStyle::with_template(
+                        "[{elapsed_precise}] {bar:40.cyan/blue} {pos:>7}/{len:7} {msg}",
+                    )
+                    .unwrap(),
+                );
+                bar
+            }
+            None => {
+                let bar = indicatif::ProgressBar::new_spinner();
+                bar.set_style(
+                    ProgressStyle::with_template(
+                        "[{elapsed_precise}] {spinner:.cyan/blue} {pos:>7}/{prefix}+ {msg}",
+                    )
+                    .unwrap(),
+                );
+                bar
+            }
+        };
 
+        bar.set_draw_target(ProgressDrawTarget::stderr_with_hz(5));
         let bar = Arc::new(bar);
         let size = Arc::new(AtomicU64::default());
+        let discovered_count = Arc::new(AtomicU64::default());
 
         let bar_weak = Arc::downgrade(&bar);
         let size_weak = Arc::downgrade(&size);
@@ -52,7 +69,30 @@ impl ProgressBar {
             }
         });
 
-        Self { bar, size }
+        Self {
+            bar,
+            size,
+            discovered_count,
+        }
+    }
+
+    pub fn set_length(&self, len: usize) {
+        self.bar.set_length(len.try_into().unwrap());
+        self.bar.set_style(
+            ProgressStyle::with_template(
+                "[{elapsed_precise}] {bar:40.cyan/blue} {pos:>7}/{len:7} {msg}",
+            )
+            .unwrap(),
+        );
+    }
+
+    pub fn notify_file_discovered(&self) {
+        self.discovered_count
+            .fetch_add(1, std::sync::atomic::Ordering::Relaxed);
+        let count = self
+            .discovered_count
+            .load(std::sync::atomic::Ordering::Relaxed);
+        self.bar.set_prefix(count.to_string());
     }
 
     pub fn notify_record_processed(&self, record_size: Option<u64>) {