diff --git a/src/sync-digest.h b/src/sync-digest.h
index d980afb..7cef28f 100644
--- a/src/sync-digest.h
+++ b/src/sync-digest.h
@@ -26,6 +26,7 @@
 #include <boost/exception/all.hpp>
 #include <openssl/evp.h>
 #include <boost/cstdint.hpp>
+#include <vector>
 
 namespace Sync {
 
@@ -134,8 +135,7 @@
   
 private:
   EVP_MD_CTX *m_context;
-  uint8_t *m_buffer;
-  uint32_t m_hashLength;
+  std::vector<uint8_t> m_buffer;
 };
 
 namespace Error {