diff --git a/libcxx/docs/ReleaseNotes/18.rst b/libcxx/docs/ReleaseNotes/18.rst
index fb3d2af544c28..450a6f25d1ea5 100644
--- a/libcxx/docs/ReleaseNotes/18.rst
+++ b/libcxx/docs/ReleaseNotes/18.rst
@@ -342,3 +342,6 @@ Build System Changes
   them so that they can interoperate with other system-provided libraries that might be using a different unwinding
   library (such as ``libgcc_s``), you should pass ``LIBCXXABI_USE_LLVM_UNWINDER=OFF`` and ``COMPILER_RT_USE_LLVM_UNWINDER=OFF``
   to make sure the system-provided unwinding library is used by the LLVM runtimes.
+
+- In Clang-cl configurations, libc++ can now be built against the static and/or
+  debug MSVC C runtimes