diff --git a/include/cuco/detail/bloom_filter/arrow_filter_policy.cuh b/include/cuco/detail/bloom_filter/arrow_filter_policy.cuh
index 747a8a490..4fc5efc29 100644
--- a/include/cuco/detail/bloom_filter/arrow_filter_policy.cuh
+++ b/include/cuco/detail/bloom_filter/arrow_filter_policy.cuh
@@ -41,8 +41,9 @@ class arrow_filter_policy {
  public:
   using hasher    = cuco::xxhash_64<Key>;  ///< xxhash_64 hasher for Arrow bloom filter policy
   using word_type = std::uint32_t;         ///< uint32_t for Arrow bloom filter policy
-  using hash_argument_type = typename hasher::argument_type;
-  using hash_result_type   = decltype(std::declval<hasher>()(std::declval<hash_argument_type>()));
+  using hash_argument_type = typename hasher::argument_type;  ///< Hash function input type
+  using hash_result_type   = decltype(std::declval<hasher>()(
+    std::declval<hash_argument_type>()));  ///< hash function output type
 
   static constexpr uint32_t bits_set_per_block = 8;  ///< hardcoded bits set per Arrow filter block
   static constexpr uint32_t words_per_block    = 8;  ///< hardcoded words per Arrow filter block