--- a/libunwind/CMakeLists.txt
+++ b/libunwind/CMakeLists.txt
@@ -176,6 +176,10 @@
 add_compile_flags_if_supported(-Werror=return-type)
 
 if (LIBUNWIND_ENABLE_CET)
+  if (NOT "libunwind" IN_LIST LLVM_ENABLE_RUNTIMES
+      AND "clang" IN_LIST LLVM_ENABLE_PROJECTS)
+    include_directories("${CMAKE_CURRENT_SOURCE_DIR}/../clang/lib/Headers")
+  endif()
   add_compile_flags_if_supported(-fcf-protection=full)
   add_compile_flags_if_supported(-mshstk)
   if (NOT CXX_SUPPORTS_FCF_PROTECTION_EQ_FULL_FLAG)