diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2b3f85d9..0a1bcb18 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -383,10 +383,10 @@ if(WIN32)
     endif()
 
     if(MSVC)
-        set(MSVC_FLAGS "-DWIN32 -DNOMINMAX -D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS -D__CRT_NONSTDC_NO_WARNINGS /MP")
+        set(MSVC_FLAGS "-DWIN32 -DNOMINMAX -D_USE_MATH_DEFINES -D_CRT_SECURE_NO_WARNINGS -D__CRT_NONSTDC_NO_WARNINGS /MP /Ox")
         if(ENABLE_SIMD)
-          if (X86 OR X86_64)
-            set(MSVC_FLAGS "${MSVC_FLAGS} /arch:SSE /arch:SSE2 /Ox")
+          if (X86)
+            set(MSVC_FLAGS "${MSVC_FLAGS} /arch:SSE /arch:SSE2")
           endif()
         endif()