diff --git a/lib/ClangImporter/ClangImporter.cpp b/lib/ClangImporter/ClangImporter.cpp
index 0734238fe52e5..39c3bc9441015 100644
--- a/lib/ClangImporter/ClangImporter.cpp
+++ b/lib/ClangImporter/ClangImporter.cpp
@@ -1211,12 +1211,12 @@ ClangImporter::Implementation::Implementation(ASTContext &ctx,
   else if (ctx.LangOpts.Target.isMacOSX()) {
     if (!ctx.LangOpts.EnableAppExtensionRestrictions) {
       PlatformAvailabilityFilter =
-      [](StringRef Platform) { return Platform == "macosx"; };
+      [](StringRef Platform) { return Platform == "macos"; };
     } else {
       PlatformAvailabilityFilter =
       [](StringRef Platform) {
-        return Platform == "macosx" ||
-               Platform == "macosx_app_extension"; };
+        return Platform == "macos" ||
+               Platform == "macos_app_extension"; };
     }
     // Anything deprecated in OSX 10.9.x and earlier is unavailable in Swift.
     DeprecatedAsUnavailableFilter =
diff --git a/lib/ClangImporter/ImportDecl.cpp b/lib/ClangImporter/ImportDecl.cpp
index 4cc7551c94246..e7dc313024bd0 100644
--- a/lib/ClangImporter/ImportDecl.cpp
+++ b/lib/ClangImporter/ImportDecl.cpp
@@ -5119,11 +5119,11 @@ void ClangImporter::Implementation::importAttributes(
       auto platformK =
         llvm::StringSwitch<Optional<PlatformKind>>(Platform)
           .Case("ios", PlatformKind::iOS)
-          .Case("macosx", PlatformKind::OSX)
+          .Case("macos", PlatformKind::OSX)
           .Case("tvos", PlatformKind::tvOS)
           .Case("watchos", PlatformKind::watchOS)
           .Case("ios_app_extension", PlatformKind::iOSApplicationExtension)
-          .Case("macosx_app_extension",
+          .Case("macos_app_extension",
                 PlatformKind::OSXApplicationExtension)
           .Case("tvos_app_extension",
                 PlatformKind::tvOSApplicationExtension)