diff --git a/src/bench/crypto_hash.cpp b/src/bench/crypto_hash.cpp
--- a/src/bench/crypto_hash.cpp
+++ b/src/bench/crypto_hash.cpp
@@ -2,8 +2,6 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
-#include <iostream>
-
 #include <bench/bench.h>
 #include <bloom.h>
 #include <crypto/ripemd160.h>
@@ -16,6 +14,9 @@
 #include <uint256.h>
 #include <util/time.h>
 
+#include <iostream>
+#include <string>
+
 /* Number of bytes to hash per iteration */
 static const uint64_t BUFFER_SIZE = 1000 * 1000;
 
@@ -65,7 +66,8 @@
     uint256 x;
     uint64_t k1 = 0;
     while (state.KeepRunning()) {
-        *((uint64_t *)x.begin()) = SipHashUint256(0, ++k1, x);
+        uint64_t hash64 = SipHashUint256(0, ++k1, x);
+        std::memcpy(x.begin(), &hash64, sizeof(hash64));
     }
 }