diff --git a/cpp/src/knn/knn.cu b/cpp/src/knn/knn.cu
index 4bf9116d28..449336ef20 100644
--- a/cpp/src/knn/knn.cu
+++ b/cpp/src/knn/knn.cu
@@ -193,6 +193,7 @@ void approx_knn_build_index(raft::handle_t& handle,
   auto index_view  = raft::make_device_matrix_view<const float, int64_t>(index_array, n, D);
 
   if (ivf_ft_pams) {
+    index->nprobe = ivf_ft_pams->nprobe;
     cuvs::neighbors::ivf_flat::index_params params;
     params.metric     = static_cast<cuvs::distance::DistanceType>(metric);
     params.metric_arg = metricArg;
@@ -201,7 +202,7 @@ void approx_knn_build_index(raft::handle_t& handle,
     index->ivf_flat = std::make_unique<cuvs::neighbors::ivf_flat::index<float, int64_t>>(
       cuvs::neighbors::ivf_flat::build(handle, params, index_view));
   } else if (ivf_pq_pams) {
-    index->nprobe = dynamic_cast<const IVFParam*>(params)->nprobe;
+    index->nprobe = ivf_pq_pams->nprobe;
     cuvs::neighbors::ivf_pq::index_params params;
     params.metric     = static_cast<cuvs::distance::DistanceType>(metric);
     params.metric_arg = metricArg;
@@ -225,18 +226,20 @@ void approx_knn_search(raft::handle_t& handle,
                        float* query_array,
                        int n)
 {
-  auto query_view =
-    raft::make_device_matrix_view<const float, int64_t>(query_array, n, index->ivf_pq->dim());
   auto indices_view   = raft::make_device_matrix_view<int64_t, int64_t>(indices, n, k);
   auto distances_view = raft::make_device_matrix_view<float, int64_t>(distances, n, k);
 
   if (index->ivf_flat) {
+    auto query_view =
+      raft::make_device_matrix_view<const float, int64_t>(query_array, n, index->ivf_flat->dim());
     cuvs::neighbors::ivf_flat::search_params params;
     params.n_probes = index->nprobe;
 
     cuvs::neighbors::ivf_flat::search(
       handle, params, *index->ivf_flat, query_view, indices_view, distances_view);
   } else if (index->ivf_pq) {
+    auto query_view =
+      raft::make_device_matrix_view<const float, int64_t>(query_array, n, index->ivf_pq->dim());
     cuvs::neighbors::ivf_pq::search_params params;
     params.n_probes = index->nprobe;