diff --git a/streams/region/region_file.cpp b/streams/region/region_file.cpp
index 87a010ef..924e13a8 100644
--- a/streams/region/region_file.cpp
+++ b/streams/region/region_file.cpp
@@ -361,11 +361,13 @@ Error RegionFile::save_block(Vector3i position, VoxelBufferInternal &block) {
 		BlockSerializer::SerializeResult res = BlockSerializer::serialize_and_compress(block);
 		ERR_FAIL_COND_V(!res.success, ERR_INVALID_PARAMETER);
 		f->store_32(res.data.size());
-		const unsigned int written_size = sizeof(int) + res.data.size();
+		const unsigned int written_size = sizeof(uint32_t) + res.data.size();
 		f->store_buffer(res.data.data(), res.data.size());
 
 		const unsigned int end_pos = f->get_position();
-		CRASH_COND(written_size != (end_pos - block_offset));
+		CRASH_COND_MSG(written_size != (end_pos - block_offset),
+				String("written_size: {0}, block_offset: {1}, end_pos: {2}")
+						.format(varray(written_size, end_pos, block_offset)));
 		pad_to_sector_size(f);
 
 		block_info.set_sector_index((block_offset - _blocks_begin_offset) / _header.format.sector_size);
@@ -389,7 +391,7 @@ Error RegionFile::save_block(Vector3i position, VoxelBufferInternal &block) {
 		BlockSerializer::SerializeResult res = BlockSerializer::serialize_and_compress(block);
 		ERR_FAIL_COND_V(!res.success, ERR_INVALID_PARAMETER);
 		const std::vector<uint8_t> &data = res.data;
-		const int written_size = sizeof(int) + data.size();
+		const int written_size = sizeof(uint32_t) + data.size();
 
 		const int new_sector_count = get_sector_count_from_bytes(written_size);
 		CRASH_COND(new_sector_count < 1);
diff --git a/streams/region/region_file.h b/streams/region/region_file.h
index dfec7d06..17bcfa34 100644
--- a/streams/region/region_file.h
+++ b/streams/region/region_file.h
@@ -61,6 +61,8 @@ struct RegionBlockInfo {
 	}
 };
 
+static_assert(sizeof(RegionBlockInfo) == 4, "Data in this struct must have a consistent size on all target platforms.");
+
 // Archive file storing voxels in a fixed sparse grid data structure.
 // The format is designed to be easily writable in chunks so it can be used for partial in-game loading and saving.
 // Inspired by https://www.seedofandromeda.com/blogs/1-creating-a-region-file-system-for-a-voxel-game