diff --git a/CMakeLists.txt b/CMakeLists.txt
index 4c796ea..684f48f 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,13 +1,5 @@
 cmake_minimum_required(VERSION 3.4.0 FATAL_ERROR)
 
-if ("${CMAKE_GENERATOR}" MATCHES "Visual Studio 15( 2017)? Win64")
-  set(MSVC_IS_2017 ON)
-elseif ("${CMAKE_GENERATOR}" STREQUAL "Visual Studio 14 2015 Win64")
-  set(MSVC_IS_2017 OFF)
-else()
-  message(FATAL_ERROR "This build script only supports building Folly on 64-bit Windows with Visual Studio 2015 or Visual Studio 2017.")
-endif()
-
 # includes
 set(CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/CMake" ${CMAKE_MODULE_PATH})
 include_directories(${CMAKE_CURRENT_SOURCE_DIR})
@@ -24,10 +16,14 @@ set_property(GLOBAL PROPERTY USE_FOLDERS ON)
 
 project(${PACKAGE_NAME} CXX)
 
-# Check architecture OS
-if (NOT CMAKE_SIZEOF_VOID_P EQUAL 8)
-  message(FATAL_ERROR "Folly requires a 64bit OS")
+if (NOT MSVC_VERSION LESS 1910)
+  set(MSVC_IS_2017 ON)
+elseif (NOT MSVC_VERSION LESS 1900)
+  set(MSVC_IS_2017 OFF)
+else()
+  message(FATAL_ERROR "This build script only supports building Folly on 64-bit Windows with Visual Studio 2015 or Visual Studio 2017.")
 endif()
+
 if(NOT "${CMAKE_SYSTEM_NAME}" STREQUAL "Windows")
   message(FATAL_ERROR "You should only be using CMake to build Folly if you are on Windows!")
 endif()