diff --git a/simd/CMakeLists.txt b/simd/CMakeLists.txt
index d67591ee..397a9f35 100755
--- a/simd/CMakeLists.txt
+++ b/simd/CMakeLists.txt
@@ -10,10 +10,6 @@ else()
     -I${CMAKE_CURRENT_SOURCE_DIR}/)
 endif()
 
-if(MSVC)
-  set(NAFLAGS ${NAFLAGS} -DMSVC)
-endif()
-
 # This only works if building from the command line.  There is currently no way
 # to set a variable's value based on the build type when using the MSVC IDE.
 if(CMAKE_BUILD_TYPE STREQUAL "Debug"