diff --git a/src/util/hwf.cpp b/src/util/hwf.cpp
index 40d20b6..afcde2d 100644
--- a/src/util/hwf.cpp
+++ b/src/util/hwf.cpp
@@ -31,7 +31,7 @@ Revision History:
 #include <fenv.h>
 #endif
 
-#ifndef _M_IA64
+#ifdef __x86_64
 #define USE_INTRINSICS
 #endif
 
@@ -51,7 +51,7 @@ Revision History:
 // Luckily, these are kind of standardized, at least for Windows/Linux/OSX.
 #ifdef __clang__
 #undef USE_INTRINSICS
-#else
+#elif defined(USE_INTRINSICS)
 #include <emmintrin.h>
 #endif