diff --git a/.gitignore b/.gitignore
index b3f097c6..e9d4f023 100644
--- a/.gitignore
+++ b/.gitignore
@@ -24,4 +24,6 @@ VERSION
 __pycache__/
 
 # Mac OS
-.DS_Store
\ No newline at end of file
+.DS_Store
+
+build/
\ No newline at end of file
diff --git a/src/core/analysis/rnn_scorer_gbeam.cc b/src/core/analysis/rnn_scorer_gbeam.cc
index f6051e9c..7e57dcf9 100644
--- a/src/core/analysis/rnn_scorer_gbeam.cc
+++ b/src/core/analysis/rnn_scorer_gbeam.cc
@@ -319,9 +319,9 @@ Status RnnScorerGbeamFactory::make(StringPiece rnnModelPath,
       state_->resolver.build(dic, state_->config, state_->rnnReader.words()));
   auto& h = state_->rnnReader.header();
   state_->embeddings = {state_->rnnReader.embeddings(), h.layerSize,
-                        h.vocabSize};
+                        static_cast<jumanpp::size_t>(h.vocabSize)};
   state_->nceEmbeddings = {state_->rnnReader.nceEmbeddings(), h.layerSize,
-                           h.vocabSize};
+                           static_cast<jumanpp::size_t>(h.vocabSize)};
   if (h.layerSize > 64 * 1024) {
     return JPPS_NOT_IMPLEMENTED << "we don't support embed sizes > 64k";
   }
diff --git a/src/core/analysis/score_processor.cc b/src/core/analysis/score_processor.cc
index 15ad2a04..8e5403b8 100644
--- a/src/core/analysis/score_processor.cc
+++ b/src/core/analysis/score_processor.cc
@@ -195,7 +195,7 @@ util::ArraySlice<BeamCandidate> processBeamCandidates(
     candidates = util::MutableArraySlice<BeamCandidate>{candidates, 0, sz};
   }
   std::sort(candidates.begin(), candidates.end(), comp);
-  auto size = std::min<u64>(maxBeam, candidates.size());
+  auto size = std::min<jumanpp::size_t>(maxBeam, candidates.size());
   return util::ArraySlice<BeamCandidate>{candidates, 0, size};
 }
 
diff --git a/src/rnn/mikolov_rnn.cc b/src/rnn/mikolov_rnn.cc
index c192e166..2bdebf58 100644
--- a/src/rnn/mikolov_rnn.cc
+++ b/src/rnn/mikolov_rnn.cc
@@ -177,29 +177,33 @@ Status MikolovModelReader::parse() {
   auto maxBlock = std::max<u64>({hdr.layerSize * hdr.vocabSize, hdr.maxentSize,
                                  hdr.layerSize * hdr.layerSize});
   // 3 comes from rounding to next value + sizeof(float)
-  auto pageSize = 1ULL << (static_cast<u32>(std::log2(maxBlock)) + 3);
+  auto pageSize = static_cast<size_t>(1) << (static_cast<u32>(std::log2(maxBlock)) + 3);
   data_->memmgr.initialize(pageSize);
   data_->alloc = data_->memmgr.value().core();
   auto& alloc = data_->alloc;
+
+  const auto embedding_matrix_size = static_cast<size_t>(hdr.layerSize) * static_cast<size_t>(hdr.vocabSize);
+  const auto transition_matrix_size = static_cast<size_t>(hdr.layerSize) * static_cast<size_t>(hdr.layerSize);
+
   data_->embeddingData =
-      alloc->allocateBuf<float>(hdr.layerSize * hdr.vocabSize, 64);
+      alloc->allocateBuf<float>(embedding_matrix_size, 64);
   data_->nceEmbeddingData =
-      alloc->allocateBuf<float>(hdr.layerSize * hdr.vocabSize, 64);
+      alloc->allocateBuf<float>(embedding_matrix_size, 64);
   data_->matrixData =
-      alloc->allocateBuf<float>(hdr.layerSize * hdr.layerSize, 64);
-  data_->maxentWeightData = alloc->allocateBuf<float>(hdr.maxentSize, 64);
+      alloc->allocateBuf<float>(transition_matrix_size, 64);
+  data_->maxentWeightData = alloc->allocateBuf<float>(static_cast<size_t>(hdr.maxentSize), 64);
 
   JPP_RIE_MSG(copyArray(contents, data_->embeddingData,
-                        hdr.layerSize * hdr.vocabSize, &start),
+                        embedding_matrix_size, &start),
               "embeds");
   JPP_RIE_MSG(copyArray(contents, data_->nceEmbeddingData,
-                        hdr.layerSize * hdr.vocabSize, &start),
+                        embedding_matrix_size, &start),
               "nce embeds");
   JPP_RIE_MSG(copyArray(contents, data_->matrixData,
-                        hdr.layerSize * hdr.layerSize, &start),
+                        transition_matrix_size, &start),
               "matrix");
   JPP_RIE_MSG(
-      copyArray(contents, data_->maxentWeightData, hdr.maxentSize, &start),
+      copyArray(contents, data_->maxentWeightData, static_cast<size_t>(hdr.maxentSize), &start),
       "maxent weights");
   if (start != contents.size()) {
     return Status::InvalidState() << "did not read rnn model file fully";
@@ -245,4 +249,4 @@ StringPiece MikolovRnn::maxentWeightsAsStringpiece() const {
 
 }  // namespace mikolov
 }  // namespace rnn
-}  // namespace jumanpp
\ No newline at end of file
+}  // namespace jumanpp