diff --git a/src/cli.rs b/src/cli.rs
index 2d2643a..3bf62f6 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -22,4 +22,6 @@ pub struct Arguments {
     /// Path to the git repository.
     #[arg(value_hint = ValueHint::DirPath, default_value = ".")]
     pub repository_path: PathBuf,
+
+    pub subtree: Option<PathBuf>,
 }
diff --git a/src/main.rs b/src/main.rs
index dd6efcb..f1c2c2a 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -18,10 +18,19 @@ fn main() -> anyhow::Result<()> {
     let repository = gix::open(arguments.repository_path)?;
 
     let mut current_commit = repository.resolve_revspec(&arguments.from)?;
-    let current_tree = current_commit
+    let mut current_tree = current_commit
         .tree()
         .context("Failed to get tree for initial commit")?;
 
+    if let Some(subtree) = &arguments.subtree {
+        let entry = current_tree
+            .lookup_entry_by_path(subtree)?
+            .expect("sub-tree not found");
+        if entry.mode().is_tree() {
+            current_tree = repository.find_tree(entry.id())?;
+        }
+    }
+
     // Build a set of the entry file names we are interested in.
     let mut interested: HashSet<_> = Default::default();
     for entry in current_tree.iter() {
@@ -69,10 +78,24 @@ fn main() -> anyhow::Result<()> {
         let parent_commit = repository
             .find_commit(parent_id)
             .context("Failed to find parent commit")?;
-        let parent_tree = parent_commit
+        let mut parent_tree = parent_commit
             .tree()
             .context("Failed to retrieve parent tree")?;
 
+        if let Some(subtree) = &arguments.subtree {
+            let Some(entry) = parent_tree.lookup_entry_by_path(subtree)? else {
+                // The subtree does not exist in this revision. Assume any
+                // remaining entries of interest belong to this commit.
+                for entry in interested.drain() {
+                    output(entry.as_bstr(), &current_commit)?;
+                }
+                break;
+            };
+            if entry.mode().is_tree() {
+                parent_tree = repository.find_tree(entry.id())?;
+            }
+        }
+
         let mut scanner = EntryScanner::new(current_tree.iter(), parent_tree.iter())?;
         while let Some(change) = scanner.next_change()? {
             if interested.remove(change.filename()) {