diff --git a/llvm/cmake/config-ix.cmake b/llvm/cmake/config-ix.cmake
index 0aae13e30f2a..aba28e40d9a2 100644
--- a/llvm/cmake/config-ix.cmake
+++ b/llvm/cmake/config-ix.cmake
@@ -266,10 +266,10 @@ set(BACKTRACE_HEADER ${Backtrace_HEADER})
 
 # Prevent check_symbol_exists from using API that is not supported for a given
 # deployment target.
-check_c_compiler_flag("-Werror=unguarded-availability-new" "C_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW")
-if(C_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW)
-  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unguarded-availability-new")
-endif()
+#check_c_compiler_flag("-Werror=unguarded-availability-new" "C_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW")
+#if(C_SUPPORTS_WERROR_UNGUARDED_AVAILABILITY_NEW)
+#  set(CMAKE_REQUIRED_FLAGS "${CMAKE_REQUIRED_FLAGS} -Werror=unguarded-availability-new")
+#endif()
 
 # Determine whether we can register EH tables.
 check_symbol_exists(__register_frame "${CMAKE_CURRENT_LIST_DIR}/unwind.h" HAVE_REGISTER_FRAME)
diff --git a/llvm/cmake/modules/HandleLLVMOptions.cmake b/llvm/cmake/modules/HandleLLVMOptions.cmake
index 5ca580fbb59c..ea0e026e5d31 100644
--- a/llvm/cmake/modules/HandleLLVMOptions.cmake
+++ b/llvm/cmake/modules/HandleLLVMOptions.cmake
@@ -668,9 +668,9 @@ if ( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" )
   append("-Werror=date-time" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
 endif( LLVM_COMPILER_IS_GCC_COMPATIBLE OR CMAKE_CXX_COMPILER_ID MATCHES "XL" )
 
-if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  append("-Werror=unguarded-availability-new" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
-endif()
+#if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+#  append("-Werror=unguarded-availability-new" CMAKE_C_FLAGS CMAKE_CXX_FLAGS)
+#endif()
 
 if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
   # LLVM data structures like llvm::User and llvm::MDNode rely on
