diff --git a/cmake/platform.cmake b/cmake/platform.cmake
index 3597970a..805ce63e 100644
--- a/cmake/platform.cmake
+++ b/cmake/platform.cmake
@@ -107,9 +107,6 @@ elseif(UNIX OR MINGW)
             append(CMAKE_CCXX_SANITIZER_FLAGS "-g -fno-omit-frame-pointer")
         endif()
     elseif("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-        if(NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
-            set(DEF_ARCH_OPT_FLAGS "-march=native -mtune=native")
-        endif()
         # suppress warning on assumptions made regarding overflow (#146)
         append(CMAKE_CCXX_NOWARN_FLAGS "-Wno-strict-overflow")
     elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Intel")