diff --git a/crt/CMakeLists.txt b/crt/CMakeLists.txt
index 9710c1ebe..6308dc7d4 100644
--- a/crt/CMakeLists.txt
+++ b/crt/CMakeLists.txt
@@ -39,13 +39,14 @@ if(UNIX AND NOT APPLE)
         if(CMAKE_C_COMPILER_ID MATCHES "GNU" AND CMAKE_C_COMPILER_VERSION VERSION_LESS "5.0")
             set(MY_ASSEMBLER_IS_TOO_OLD_FOR_512AVX ON CACHE BOOL "Disable AVX512 on old GCC that not supports it")
         endif()
-        if(CMAKE_C_COMPILER_ID MATCHES "GNU" AND CMAKE_SYSTEM_PROCESSOR MATCHES "x86|X86|i386|i686")
+
+        string(TOLOWER "${CMAKE_SYSTEM_PROCESSOR}" CMAKE_SYSTEM_PROCESSOR_LOWER)
+
+        if(CMAKE_SYSTEM_PROCESSOR_LOWER MATCHES "x86_64|amd64" AND CMAKE_SIZEOF_VOID_P EQUAL 4 OR CMAKE_SYSTEM_PROCESSOR_LOWER MATCHES "x86|i386|i686")
             set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -msse2")
         endif()
-        message(STATUS "XXXXXXXXX CMAKE_C_FLAGS: ${CMAKE_C_FLAGS}")
-        message(STATUS "XXXXXXXXX CMAKE_SYSTEM_PROCESSOR: ${CMAKE_SYSTEM_PROCESSOR}")
-
 
+        message(STATUS "XXXXXXXXX CMAKE_C_FLAGS: ${CMAKE_C_FLAGS}")
         add_subdirectory(aws-lc)
     endif()