--- llvm-project/compiler-rt/CMakeLists.txt
+++ llvm-project/compiler-rt/CMakeLists.txt
@@ -368,6 +368,8 @@ if(CMAKE_CXX_COMPILER_ID MATCHES Clang)
   list(APPEND SANITIZER_COMMON_CFLAGS ${THREAD_SAFETY_FLAGS})
   string(REPLACE ";" " " thread_safety_flags_space_sep "${THREAD_SAFETY_FLAGS}")
   string(APPEND COMPILER_RT_TEST_COMPILER_CFLAGS " ${thread_safety_flags_space_sep}")
+  list(APPEND NO_THREAD_SAFETY_FLAGS ${THREAD_SAFETY_FLAGS})
+  list(TRANSFORM NO_THREAD_SAFETY_FLAGS REPLACE "error=" "no-")
 endif()
 
 # If we're using MSVC,
@@ -536,6 +538,7 @@ set(COMPILER_RT_GTEST_CFLAGS
   -DGTEST_HAS_RTTI=0
   -I${COMPILER_RT_GTEST_PATH}/include
   -I${COMPILER_RT_GTEST_PATH}
+  ${NO_THREAD_SAFETY_FLAGS}
 )
 
 # Mocking support.