diff --git a/topiary-core/src/atom_collection.rs b/topiary-core/src/atom_collection.rs
index b225329e..06c55acb 100644
--- a/topiary-core/src/atom_collection.rs
+++ b/topiary-core/src/atom_collection.rs
@@ -93,7 +93,7 @@ impl AtomCollection {
         root: &Node,
         source: &[u8],
         specified_leaf_nodes: HashSet<usize>,
-        comments: Vec<AnchoredComment>,
+        mut comments: Vec<AnchoredComment>,
     ) -> FormatterResult<Self> {
         // Flatten the tree, from the root node, in a depth-first traversal
         let dfs_nodes = dfs_flatten(root);
@@ -117,7 +117,7 @@ impl AtomCollection {
             counter: 0,
         };
 
-        atoms.collect_leafs_inner(root, source, &comments, &Vec::new(), 0)?;
+        atoms.collect_leafs_inner(root, source, &mut comments, &Vec::new(), 0)?;
 
         Ok(atoms)
     }