diff --git a/libcxx/test/libcxx/strings/c.strings/version_cuchar.pass.cpp b/libcxx/test/libcxx/strings/c.strings/version_cuchar.pass.cpp
--- a/libcxx/test/libcxx/strings/c.strings/version_cuchar.pass.cpp
+++ b/libcxx/test/libcxx/strings/c.strings/version_cuchar.pass.cpp
@@ -8,6 +8,11 @@
 //
 // XFAIL: *
 
+// Skip this test on windows. If built on top of the MSVC runtime, the
+// <cuchar> header actually does exist (although not provided by us).
+// This should be removed once D97870 has landed.
+// UNSUPPORTED: windows
+
 // <cuchar>
 
 #include <cuchar>
diff --git a/libcxx/test/std/strings/c.strings/cuchar.pass.cpp b/libcxx/test/std/strings/c.strings/cuchar.pass.cpp
--- a/libcxx/test/std/strings/c.strings/cuchar.pass.cpp
+++ b/libcxx/test/std/strings/c.strings/cuchar.pass.cpp
@@ -8,6 +8,11 @@
 //
 // XFAIL: libc++
 
+// Skip this test on windows. If built on top of the MSVC runtime, the
+// <cuchar> header actually does exist (although not provided by us).
+// This should be removed once D97870 has landed.
+// UNSUPPORTED: windows
+
 // <cuchar>
 
 #include <cuchar>