diff --git a/src/index.cpp b/src/index.cpp
index bf93344fa..d44a79e4d 100644
--- a/src/index.cpp
+++ b/src/index.cpp
@@ -962,6 +962,7 @@ std::pair<uint32_t, uint32_t> Index<T, TagT, LabelT>::iterate_to_fixed_point(
             }
         }
 
+        dist_scratch.resize(id_scratch.size());
         assert(dist_scratch.capacity() >= id_scratch.size());
         compute_dists(id_scratch, dist_scratch);
         cmps += (uint32_t)id_scratch.size();