diff --git a/cpp/bench.cpp b/cpp/bench.cpp
index 2801ccc0..dad0353f 100644
--- a/cpp/bench.cpp
+++ b/cpp/bench.cpp
@@ -47,6 +47,7 @@
 using namespace unum::usearch;
 using namespace unum;
 
+using label_t = std::int64_t;
 using vector_id_t = std::uint32_t;
 using vector_view_t = span_gt<float const>;
 
@@ -534,24 +535,24 @@ void run_big_or_small(dataset_at& dataset, args_t const& args, index_config_t co
     if (args.native) {
         if (args.metric_cos) {
             std::printf("-- Metric: Angular\n");
-            run_typed<index_gt<cos_gt<float>, std::size_t, neighbor_id_at>>(dataset, args, config, limits);
+            run_typed<index_gt<cos_gt<float>, label_t, neighbor_id_at>>(dataset, args, config, limits);
         } else if (args.metric_l2) {
             std::printf("-- Metric: Euclidean\n");
-            run_typed<index_gt<l2sq_gt<float>, std::size_t, neighbor_id_at>>(dataset, args, config, limits);
+            run_typed<index_gt<l2sq_gt<float>, label_t, neighbor_id_at>>(dataset, args, config, limits);
         } else if (args.metric_haversine) {
             std::printf("-- Metric: Haversine\n");
-            run_typed<index_gt<haversine_gt<float>, std::size_t, neighbor_id_at>>(dataset, args, config, limits);
+            run_typed<index_gt<haversine_gt<float>, label_t, neighbor_id_at>>(dataset, args, config, limits);
         } else {
             std::printf("-- Metric: Inner Product\n");
-            run_typed<index_gt<ip_gt<float>, std::size_t, neighbor_id_at>>(dataset, args, config, limits);
+            run_typed<index_gt<ip_gt<float>, label_t, neighbor_id_at>>(dataset, args, config, limits);
         }
     } else
-        run_punned<index_punned_dense_gt<std::size_t, neighbor_id_at>>(dataset, args, config, limits);
+        run_punned<index_punned_dense_gt<label_t, neighbor_id_at>>(dataset, args, config, limits);
 }
 
 void report_alternative_setups() {
     using set_member_t = std::uint32_t;
-    using sets_index_t = index_gt<jaccard_gt<set_member_t>, std::size_t, std::uint32_t>;
+    using sets_index_t = index_gt<jaccard_gt<set_member_t>, label_t, std::uint32_t>;
     set_member_t set_a[] = {10, 12, 15};
     set_member_t set_b[] = {11, 12, 15, 16};
     sets_index_t index;
@@ -684,7 +685,11 @@ int main(int argc, char** argv) {
     // std::printf("-- Expansion @ Search: %zu\n", config.expansion_search);
 
     if (args.big)
+#ifdef USEARCH_64BIT_ENV
         run_big_or_small<uint40_t>(dataset, args, config, limits);
+#else
+        std::printf("Error: Don't use 40 bit identifiers in 32bit environment\n");
+#endif
     else
         run_big_or_small<std::uint32_t>(dataset, args, config, limits);
 
diff --git a/include/usearch/index.hpp b/include/usearch/index.hpp
index f15712c8..24d95609 100644
--- a/include/usearch/index.hpp
+++ b/include/usearch/index.hpp
@@ -41,6 +41,13 @@
 #define USEARCH_DEFINED_ARM
 #endif
 
+// Inferring hardware bitness: 32 vs 64
+#if __WORDSIZE == 64
+#define USEARCH_64BIT_ENV
+#else
+#define USEARCH_32BIT_ENV
+#endif
+
 #if !defined(USEARCH_USE_OPENMP)
 #define USEARCH_USE_OPENMP 0
 #endif
@@ -169,9 +176,9 @@ inline std::size_t ceil2(std::size_t v) noexcept {
     v |= v >> 4;
     v |= v >> 8;
     v |= v >> 16;
-    // For 64 bit systems
-    if constexpr (sizeof(void*) == 8)
-        v |= v >> 32;
+#ifdef USEARCH_64BIT_ENV
+    v |= v >> 32;
+#endif
     v++;
     return v;
 }
@@ -971,6 +978,8 @@ class sorted_buffer_gt {
 
 /**
  *  @brief Five-byte integer type to address node clouds with over 4B entries.
+ *
+ * @note Avoid usage in 32bit environment
  */
 class usearch_pack_m uint40_t {
     unsigned char octets[5];
@@ -1299,7 +1308,7 @@ struct viewed_file_t {
  *
  */
 template <typename metric_at = ip_gt<float>,            //
-          typename label_at = std::size_t,              //
+          typename label_at = std::int64_t,             //
           typename id_at = std::uint32_t,               //
           typename allocator_at = std::allocator<char>, //
           typename point_allocator_at = allocator_at>   //