diff --git a/src/nnue/nnue_accumulator.cpp b/src/nnue/nnue_accumulator.cpp
index 3ed729ffb..e63a68cb7 100644
--- a/src/nnue/nnue_accumulator.cpp
+++ b/src/nnue/nnue_accumulator.cpp
@@ -18,7 +18,6 @@
 
 #include "nnue_accumulator.h"
 
-#include <algorithm>
 #include <cassert>
 #include <cstdint>
 #include <new>
@@ -338,22 +337,23 @@ struct AccumulatorUpdateContext {
         };
 
         fused_row_reduce<Vec16Wrapper, Dimensions, ops...>(
-          (from.template acc<Dimensions>()).accumulation[perspective],
-          (to.template acc<Dimensions>()).accumulation[perspective], to_weight_vector(indices)...);
+          (from.template acc<Dimensions>()).accumulation[perspective].data(),
+          (to.template acc<Dimensions>()).accumulation[perspective].data(),
+          to_weight_vector(indices)...);
 
         fused_row_reduce<Vec32Wrapper, PSQTBuckets, ops...>(
-          (from.template acc<Dimensions>()).psqtAccumulation[perspective],
-          (to.template acc<Dimensions>()).psqtAccumulation[perspective],
+          (from.template acc<Dimensions>()).psqtAccumulation[perspective].data(),
+          (to.template acc<Dimensions>()).psqtAccumulation[perspective].data(),
           to_psqt_weight_vector(indices)...);
     }
 
     void apply(const typename FeatureSet::IndexList& added,
                const typename FeatureSet::IndexList& removed) {
-        const auto fromAcc = from.template acc<Dimensions>().accumulation[perspective];
-        const auto toAcc   = to.template acc<Dimensions>().accumulation[perspective];
+        const auto& fromAcc = from.template acc<Dimensions>().accumulation[perspective];
+        auto&       toAcc   = to.template acc<Dimensions>().accumulation[perspective];
 
-        const auto fromPsqtAcc = from.template acc<Dimensions>().psqtAccumulation[perspective];
-        const auto toPsqtAcc   = to.template acc<Dimensions>().psqtAccumulation[perspective];
+        const auto& fromPsqtAcc = from.template acc<Dimensions>().psqtAccumulation[perspective];
+        auto&       toPsqtAcc   = to.template acc<Dimensions>().psqtAccumulation[perspective];
 
 #ifdef VECTOR
         using Tiling = SIMDTiling<Dimensions, Dimensions, PSQTBuckets>;
@@ -448,8 +448,8 @@ struct AccumulatorUpdateContext {
 
 #else
 
-        std::copy_n(fromAcc, Dimensions, toAcc);
-        std::copy_n(fromPsqtAcc, PSQTBuckets, toPsqtAcc);
+        toAcc     = fromAcc;
+        toPsqtAcc = fromPsqtAcc;
 
         for (const auto index : removed)
         {
@@ -589,13 +589,10 @@ void update_accumulator_incremental(
         auto&       targetAcc = target_state.template acc<TransformedFeatureDimensions>();
         const auto& sourceAcc = computed.template acc<TransformedFeatureDimensions>();
 
-        std::memcpy(targetAcc.accumulation[perspective], sourceAcc.accumulation[perspective],
-                    sizeof(targetAcc.accumulation[perspective]));
-        std::memcpy(targetAcc.psqtAccumulation[perspective],
-                    sourceAcc.psqtAccumulation[perspective],
-                    sizeof(targetAcc.psqtAccumulation[perspective]));
+        targetAcc.accumulation[perspective]     = sourceAcc.accumulation[perspective];
+        targetAcc.psqtAccumulation[perspective] = sourceAcc.psqtAccumulation[perspective];
+        targetAcc.computed[perspective]         = true;
 
-        targetAcc.computed[perspective] = true;
         return;
     }
 
@@ -643,15 +640,16 @@ void update_accumulator_incremental(
     (target_state.template acc<TransformedFeatureDimensions>()).computed[perspective] = true;
 }
 
-Bitboard get_changed_pieces(const Piece oldPieces[SQUARE_NB], const Piece newPieces[SQUARE_NB]) {
+Bitboard get_changed_pieces(const std::array<Piece, SQUARE_NB>& oldPieces,
+                            const std::array<Piece, SQUARE_NB>& newPieces) {
 #if defined(USE_AVX512) || defined(USE_AVX2)
     static_assert(sizeof(Piece) == 1);
     Bitboard sameBB = 0;
 
     for (int i = 0; i < 64; i += 32)
     {
-        const __m256i old_v = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(oldPieces + i));
-        const __m256i new_v = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(newPieces + i));
+        const __m256i old_v = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(&oldPieces[i]));
+        const __m256i new_v = _mm256_loadu_si256(reinterpret_cast<const __m256i*>(&newPieces[i]));
         const __m256i cmpEqual        = _mm256_cmpeq_epi8(old_v, new_v);
         const std::uint32_t equalMask = _mm256_movemask_epi8(cmpEqual);
         sameBB |= static_cast<Bitboard>(equalMask) << i;
@@ -680,7 +678,7 @@ void update_accumulator_refresh_cache(Color                                 pers
     auto&                    entry = cache[ksq][perspective];
     PSQFeatureSet::IndexList removed, added;
 
-    const Bitboard changedBB = get_changed_pieces(entry.pieces, pos.piece_array().data());
+    const Bitboard changedBB = get_changed_pieces(entry.pieces, pos.piece_array());
     Bitboard       removedBB = changedBB & entry.pieceBB;
     Bitboard       addedBB   = changedBB & pos.pieces();
 
@@ -696,7 +694,7 @@ void update_accumulator_refresh_cache(Color                                 pers
     }
 
     entry.pieceBB = pos.pieces();
-    std::copy_n(pos.piece_array().begin(), SQUARE_NB, entry.pieces);
+    entry.pieces  = pos.piece_array();
 
     auto& accumulator                 = accumulatorState.acc<Dimensions>();
     accumulator.computed[perspective] = true;
@@ -812,12 +810,8 @@ void update_accumulator_refresh_cache(Color                                 pers
 
     // The accumulator of the refresh entry has been updated.
     // Now copy its content to the actual accumulator we were refreshing.
-
-    std::memcpy(accumulator.accumulation[perspective], entry.accumulation.data(),
-                sizeof(BiasType) * Dimensions);
-
-    std::memcpy(accumulator.psqtAccumulation[perspective], entry.psqtAccumulation.data(),
-                sizeof(int32_t) * PSQTBuckets);
+    accumulator.accumulation[perspective]     = entry.accumulation;
+    accumulator.psqtAccumulation[perspective] = entry.psqtAccumulation;
 #endif
 }
 
diff --git a/src/nnue/nnue_accumulator.h b/src/nnue/nnue_accumulator.h
index 181412b43..69ab49632 100644
--- a/src/nnue/nnue_accumulator.h
+++ b/src/nnue/nnue_accumulator.h
@@ -46,9 +46,9 @@ class FeatureTransformer;
 // Class that holds the result of affine transformation of input features
 template<IndexType Size>
 struct alignas(CacheLineSize) Accumulator {
-    std::int16_t               accumulation[COLOR_NB][Size];
-    std::int32_t               psqtAccumulation[COLOR_NB][PSQTBuckets];
-    std::array<bool, COLOR_NB> computed = {};
+    std::array<std::array<std::int16_t, Size>, COLOR_NB>        accumulation;
+    std::array<std::array<std::int32_t, PSQTBuckets>, COLOR_NB> psqtAccumulation;
+    std::array<bool, COLOR_NB>                                  computed = {};
 };
 
 
@@ -71,7 +71,7 @@ struct AccumulatorCaches {
         struct alignas(CacheLineSize) Entry {
             std::array<BiasType, Size>              accumulation;
             std::array<PSQTWeightType, PSQTBuckets> psqtAccumulation;
-            Piece                                   pieces[SQUARE_NB];
+            std::array<Piece, SQUARE_NB>            pieces;
             Bitboard                                pieceBB;
 
             // To initialize a refresh entry, we set all its bitboards empty,