diff --git a/libcxx/cmake/config-ix.cmake b/libcxx/cmake/config-ix.cmake
index cedc76792879..a7a684c9d5f0 100644
--- a/libcxx/cmake/config-ix.cmake
+++ b/libcxx/cmake/config-ix.cmake
@@ -76,15 +76,6 @@ if(NOT WIN32 OR MINGW)
   include(CheckLibcxxAtomic)
 endif()
 
-# Check compiler flags
-
-check_cxx_compiler_flag(/WX                     LIBCXX_HAS_WX_FLAG)
-check_cxx_compiler_flag(/WX-                    LIBCXX_HAS_NO_WX_FLAG)
-check_cxx_compiler_flag(/EHsc                   LIBCXX_HAS_EHSC_FLAG)
-check_cxx_compiler_flag(/EHs-                   LIBCXX_HAS_NO_EHS_FLAG)
-check_cxx_compiler_flag(/EHa-                   LIBCXX_HAS_NO_EHA_FLAG)
-check_cxx_compiler_flag(/GR-                    LIBCXX_HAS_NO_GR_FLAG)
-
 # Check libraries
 if(WIN32 AND NOT MINGW)
   # TODO(compnerd) do we want to support an emulation layer that allows for the
diff --git a/libcxxabi/cmake/config-ix.cmake b/libcxxabi/cmake/config-ix.cmake
index 04d58fcc98d9..9195dfc74e19 100644
--- a/libcxxabi/cmake/config-ix.cmake
+++ b/libcxxabi/cmake/config-ix.cmake
@@ -62,38 +62,7 @@ int main() { return 0; }
 endif()
 
 # Check compiler flags
-check_c_compiler_flag(-funwind-tables         LIBCXXABI_HAS_FUNWIND_TABLES)
-check_cxx_compiler_flag(-fno-exceptions       LIBCXXABI_HAS_NO_EXCEPTIONS_FLAG)
-check_cxx_compiler_flag(-fno-rtti             LIBCXXABI_HAS_NO_RTTI_FLAG)
-check_cxx_compiler_flag(-fstrict-aliasing     LIBCXXABI_HAS_FSTRICT_ALIASING_FLAG)
-check_cxx_compiler_flag(-nostdinc++           LIBCXXABI_HAS_NOSTDINCXX_FLAG)
-check_cxx_compiler_flag(-Wall                 LIBCXXABI_HAS_WALL_FLAG)
-check_cxx_compiler_flag(-W                    LIBCXXABI_HAS_W_FLAG)
-check_cxx_compiler_flag(-Wunused-function     LIBCXXABI_HAS_WUNUSED_FUNCTION_FLAG)
-check_cxx_compiler_flag(-Wunused-variable     LIBCXXABI_HAS_WUNUSED_VARIABLE_FLAG)
-check_cxx_compiler_flag(-Wunused-parameter    LIBCXXABI_HAS_WUNUSED_PARAMETER_FLAG)
-check_cxx_compiler_flag(-Wstrict-aliasing     LIBCXXABI_HAS_WSTRICT_ALIASING_FLAG)
-check_cxx_compiler_flag(-Wstrict-overflow     LIBCXXABI_HAS_WSTRICT_OVERFLOW_FLAG)
-check_cxx_compiler_flag(-Wwrite-strings       LIBCXXABI_HAS_WWRITE_STRINGS_FLAG)
-check_cxx_compiler_flag(-Wchar-subscripts     LIBCXXABI_HAS_WCHAR_SUBSCRIPTS_FLAG)
-check_cxx_compiler_flag(-Wmismatched-tags     LIBCXXABI_HAS_WMISMATCHED_TAGS_FLAG)
-check_cxx_compiler_flag(-Wmissing-braces      LIBCXXABI_HAS_WMISSING_BRACES_FLAG)
-check_cxx_compiler_flag(-Wshorten-64-to-32    LIBCXXABI_HAS_WSHORTEN_64_TO_32_FLAG)
-check_cxx_compiler_flag(-Wsign-conversion     LIBCXXABI_HAS_WSIGN_CONVERSION_FLAG)
-check_cxx_compiler_flag(-Wsign-compare        LIBCXXABI_HAS_WSIGN_COMPARE_FLAG)
-check_cxx_compiler_flag(-Wshadow              LIBCXXABI_HAS_WSHADOW_FLAG)
-check_cxx_compiler_flag(-Wconversion          LIBCXXABI_HAS_WCONVERSION_FLAG)
-check_cxx_compiler_flag(-Wnewline-eof         LIBCXXABI_HAS_WNEWLINE_EOF_FLAG)
-check_cxx_compiler_flag(-Wundef               LIBCXXABI_HAS_WUNDEF_FLAG)
-check_cxx_compiler_flag(-pedantic             LIBCXXABI_HAS_PEDANTIC_FLAG)
-check_cxx_compiler_flag(-Werror               LIBCXXABI_HAS_WERROR_FLAG)
-check_cxx_compiler_flag(-Wno-error            LIBCXXABI_HAS_WNO_ERROR_FLAG)
-check_cxx_compiler_flag(/WX                   LIBCXXABI_HAS_WX_FLAG)
-check_cxx_compiler_flag(/WX-                  LIBCXXABI_HAS_NO_WX_FLAG)
-check_cxx_compiler_flag(/EHsc                 LIBCXXABI_HAS_EHSC_FLAG)
-check_cxx_compiler_flag(/EHs-                 LIBCXXABI_HAS_NO_EHS_FLAG)
-check_cxx_compiler_flag(/EHa-                 LIBCXXABI_HAS_NO_EHA_FLAG)
-check_cxx_compiler_flag(/GR-                  LIBCXXABI_HAS_NO_GR_FLAG)
+check_cxx_compiler_flag(-nostdinc++ LIBCXXABI_HAS_NOSTDINCXX_FLAG)
 
 # Check libraries
 check_library_exists(dl dladdr "" LIBCXXABI_HAS_DL_LIB)