diff --git a/tvix/store/src/import.rs b/tvix/store/src/import.rs
index ade700a6c..206e5eaba 100644
--- a/tvix/store/src/import.rs
+++ b/tvix/store/src/import.rs
@@ -56,7 +56,7 @@ impl From<super::Error> for Error {
 // It assumes the caller adds returned nodes to the directories it assembles.
 #[instrument(skip_all, fields(entry.file_type=?&entry.file_type(),entry.path=?entry.path()))]
 fn process_entry<BS: BlobService, DP: DirectoryPutter>(
-    blob_service: &mut BS,
+    blob_service: &BS,
     directory_putter: &mut DP,
     entry: &walkdir::DirEntry,
     maybe_directory: Option<proto::Directory>,
@@ -145,8 +145,8 @@ fn process_entry<BS: BlobService, DP: DirectoryPutter>(
 /// naming scheme.
 #[instrument(skip(blob_service, directory_service), fields(path=?p))]
 pub fn ingest_path<BS: BlobService, DS: DirectoryService, P: AsRef<Path> + Debug>(
-    blob_service: &mut BS,
-    directory_service: &mut DS,
+    blob_service: &BS,
+    directory_service: &DS,
     p: P,
 ) -> Result<proto::node::Node, Error> {
     // Probe if the path points to a symlink. If it does, we process it manually,
diff --git a/tvix/store/src/store_io.rs b/tvix/store/src/store_io.rs
index e4c45f9e5..a7467362d 100644
--- a/tvix/store/src/store_io.rs
+++ b/tvix/store/src/store_io.rs
@@ -96,7 +96,7 @@ impl<BS: BlobService, DS: DirectoryService, PS: PathInfoService, NCS: NARCalcula
             }
         };
 
-        directoryservice::traverse_to(&mut self.directory_service, root_node, sub_path)
+        directoryservice::traverse_to(&self.directory_service, root_node, sub_path)
     }
 
     /// Imports a given path on the filesystem into the store, and returns the
@@ -110,9 +110,8 @@ impl<BS: BlobService, DS: DirectoryService, PS: PathInfoService, NCS: NARCalcula
         path: &std::path::Path,
     ) -> Result<crate::proto::PathInfo, io::Error> {
         // Call [import::ingest_path], which will walk over the given path and return a root_node.
-        let root_node =
-            import::ingest_path(&mut self.blob_service, &mut self.directory_service, path)
-                .expect("error during import_path");
+        let root_node = import::ingest_path(&self.blob_service, &self.directory_service, path)
+            .expect("error during import_path");
 
         // Render the NAR
         let (nar_size, nar_sha256) = self