diff --git a/clang/lib/Lex/ModuleMap.cpp b/clang/lib/Lex/ModuleMap.cpp
--- a/clang/lib/Lex/ModuleMap.cpp
+++ b/clang/lib/Lex/ModuleMap.cpp
@@ -2026,8 +2026,7 @@
     ActiveModule->IsSystem = true;
   if (Attrs.IsExternC)
     ActiveModule->IsExternC = true;
-  if (Attrs.NoUndeclaredIncludes ||
-      (!ActiveModule->Parent && ModuleName == "Darwin"))
+  if (Attrs.NoUndeclaredIncludes)
     ActiveModule->NoUndeclaredIncludes = true;
   ActiveModule->Directory = Directory;