diff --git a/Eigen/Core b/Eigen/Core
index ea9b86531..4401a4e14 100644
--- a/Eigen/Core
+++ b/Eigen/Core
@@ -167,7 +167,7 @@
 #endif
 
 // required for __cpuid, needs to be included after cmath
-#if defined(_MSC_VER) && (defined(_M_IX86)||defined(_M_IX64))
+#if defined(_MSC_VER) && (defined(_M_IX86)||defined(_M_X64))
   #include <intrin.h>
 #endif