diff --git a/ext/cityhash/city.cpp b/ext/cityhash/city.cpp
index 54cc2a727c..4e25788eab 100644
--- a/ext/cityhash/city.cpp
+++ b/ext/cityhash/city.cpp
@@ -27,6 +27,9 @@
 // possible hash functions, by using SIMD instructions, or by
 // compromising on hash quality.
 
+#ifndef __WIN32__
+#undef __SSE4_2__
+#endif
 #include "city.h"
 
 #include <algorithm>