Index: cmake/modules/HandleLLVMOptions.cmake
===================================================================
--- cmake/modules/HandleLLVMOptions.cmake
+++ cmake/modules/HandleLLVMOptions.cmake
@@ -16,7 +16,7 @@
     if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.7)
       message(FATAL_ERROR "Host GCC version must be at least 4.7!")
     endif()
-  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND NOT (CMAKE_CXX_SIMULATE_ID MATCHES "MSVC") )
     if(CMAKE_CXX_COMPILER_VERSION VERSION_LESS 3.1)
       message(FATAL_ERROR "Host Clang version must be at least 3.1!")
     endif()
@@ -47,6 +47,10 @@
       message(WARNING "Host Visual Studio should at least be 2013 Update 4 (MSVC 18.0.31101)"
         "  due to miscompiles from earlier versions")
     endif()
+  elseif(CMAKE_CXX_COMPILER_ID STREQUAL "Clang" AND CMAKE_CXX_SIMULATE_ID MATCHES "MSVC")
+    if (CMAKE_CXX_SIMULATE_VERSION VERSION_LESS 18.0)
+      message(FATAL_ERROR "Host Clang must have at least -fms-compatibility-version=18.0")
+    endif()
   endif()
 endif()