diff --git a/rust/lance/src/index/vector/pq.rs b/rust/lance/src/index/vector/pq.rs
index faf9a71b8c..e638d2729b 100644
--- a/rust/lance/src/index/vector/pq.rs
+++ b/rust/lance/src/index/vector/pq.rs
@@ -310,6 +310,7 @@ impl VectorIndex for PQIndex {
     }
 
     async fn remap(&mut self, mapping: &HashMap<u64, Option<u64>>) -> Result<()> {
+        let num_vectors = self.row_ids.as_ref().unwrap().len();
         let code = self
             .code
             .as_ref()