diff --git a/platform/darwin/README.md b/platform/darwin/README.md
index cbeaf844a..43e229028 100644
--- a/platform/darwin/README.md
+++ b/platform/darwin/README.md
@@ -2,6 +2,9 @@
 
 The code in the Darwin platform targets Apple platforms but is not specific
 to iOS or OS X. This code is not distributed as an SDK in itself, but is required
-by the [iOS](https://github.com/mapbox/mapbox-gl-native/tree/master/platform/ios)
-and [OS X](https://github.com/mapbox/mapbox-gl-native/tree/master/platform/osx)
-platforms.
+by the [Mapbox iOS SDK](https://github.com/mapbox/mapbox-gl-native/tree/master/platform/ios)
+and [Mapbox OS X SDK](https://github.com/mapbox/mapbox-gl-native/tree/master/platform/osx).
+
+These files depend on the Foundation and Core Foundation frameworks but do not
+depend on iOS- or OS X–specific frameworks, such as UIKit or AppKit. Any
+non-cross-platform code is guarded by TargetConditionals.h macros.