diff --git a/src/crypto/slow-hash.c b/src/crypto/slow-hash.c
index 7f2d495..2febce1 100644
--- a/src/crypto/slow-hash.c
+++ b/src/crypto/slow-hash.c
@@ -37,7 +37,7 @@
 #include "hash-ops.h"
 #include "oaes_lib.h"
 
-#if 0// defined(__x86_64__)
+#if defined(__x86_64__)
 // Optimised code below, uses x86-specific intrinsics, SSE2, AES-NI
 // Fall back to more portable code is down at the bottom