diff --git a/generator.h b/generator.h
index 3952190..f4f8d2a 100644
--- a/generator.h
+++ b/generator.h
@@ -6,6 +6,7 @@
 #include <cryptopp/secblock.h>
 #include <cryptopp/serpent.h>
 
+#include <array>
 #include <chrono>
 #include <cstdint>
 #include <mutex>
@@ -48,11 +49,14 @@ private:
 	struct G_state {
 		// 32*8
 		static constexpr const std::size_t k_length{32};
+		static constexpr const std::size_t ctr_len{16};
+
 		CryptoPP::FixedSizeSecBlock<CryptoPP::byte, k_length> k;
 #pragma GCC diagnostic push
 #pragma GCC diagnostic ignored "-Wpedantic"
 		unsigned __int128 ctr;
 #pragma GCC diagnostic pop
+		std::array<std::byte, ctr_len> counter;
 	};
 	G_state G;