diff --git a/src/backup/chunk_store.rs b/src/backup/chunk_store.rs
index 06b6b74c..9a95e8ca 100644
--- a/src/backup/chunk_store.rs
+++ b/src/backup/chunk_store.rs
@@ -193,7 +193,7 @@ impl ChunkStore {
         &self,
         print_percentage: bool,
     ) -> Result<
-        impl Iterator<Item = Result<tools::fs::ReadDirEntry, Error>>,
+        impl Iterator<Item = Result<tools::fs::ReadDirEntry, Error>> + std::iter::FusedIterator,
         Error
     > {
         use nix::dir::Dir;