diff --git a/src/hnsw/build.c b/src/hnsw/build.c
index e9d68e215..3ede9488f 100644
--- a/src/hnsw/build.c
+++ b/src/hnsw/build.c
@@ -467,6 +467,10 @@ static void BuildIndex(Relation heap, Relation index, IndexInfo *indexInfo, ldb_
     opts.retriever = ldb_wal_index_node_retriever;
     opts.retriever_mut = ldb_wal_index_node_retriever_mut;
 
+    // use palloc and pfree
+    opts.alloc_func = palloc;
+    opts.free_func = pfree;
+
     buildstate->usearch_index = usearch_init(&opts, buildstate->pq_codebook, &error);
     elog(INFO, "done init usearch index");
     assert(error == NULL);
@@ -590,6 +594,10 @@ static void BuildEmptyIndex(Relation index, IndexInfo *indexInfo, ldb_HnswBuildS
         assert(0 < opts.num_centroids && opts.num_centroids <= 256);
     }
 
+    // use palloc and pfree
+    opts.alloc_func = palloc;
+    opts.free_func = pfree;
+
     buildstate->usearch_index = usearch_init(&opts, buildstate->pq_codebook, &error);
     assert(error == NULL);
 
diff --git a/src/hnsw/insert.c b/src/hnsw/insert.c
index a9927565f..b05f88099 100644
--- a/src/hnsw/insert.c
+++ b/src/hnsw/insert.c
@@ -133,6 +133,11 @@ bool ldb_aminsert(Relation         index,
         assert(tmp_num_centroids == hdr->num_centroids);
         assert(tmp_num_subvectors == hdr->num_subvectors);
     }
+
+    // use palloc and pfree
+    opts.alloc_func = palloc;
+    opts.free_func = pfree;
+
     // todo:: do usearch init in indexInfo->ii_AmCache
     uidx = usearch_init(&opts, insertstate->pq_codebook, &error);
     if(uidx == NULL) {
diff --git a/src/hnsw/scan.c b/src/hnsw/scan.c
index 17bb63a3f..10a29e3b0 100644
--- a/src/hnsw/scan.c
+++ b/src/hnsw/scan.c
@@ -92,6 +92,10 @@ IndexScanDesc ldb_ambeginscan(Relation index, int nkeys, int norderbys)
              opts.expansion_add,
              opts.expansion_search);
 
+    // use palloc and pfree
+    opts.alloc_func = palloc;
+    opts.free_func = pfree;
+
     scanstate->usearch_index = usearch_init(&opts, scanstate->pq_codebook, &error);
     if(error != NULL) elog(ERROR, "error loading index: %s", error);
     assert(error == NULL);