diff --git a/stdlib/public/Platform/vcruntime.modulemap b/stdlib/public/Platform/vcruntime.modulemap
index f11bdf11de100..c02feff014b30 100644
--- a/stdlib/public/Platform/vcruntime.modulemap
+++ b/stdlib/public/Platform/vcruntime.modulemap
@@ -707,11 +707,6 @@ module std [system] {
       export *
     }
 
-    explicit module xstddef {
-      header "xstddef"
-      export *
-    }
-
     explicit module xstring {
       header "xstring"
       export *