diff --git a/platform/darwin/src/MGLAccountManager.h b/platform/darwin/src/MGLAccountManager.h
index d1983a4dd..a99004298 100644
--- a/platform/darwin/src/MGLAccountManager.h
+++ b/platform/darwin/src/MGLAccountManager.h
@@ -34,7 +34,7 @@ MGL_EXPORT
     and the type `String`. Alternatively, you may call this method from your
     application delegate’s `-applicationDidFinishLaunching:` method.
  */
-@property (class, assign, nullable) NSString *accessToken;
+@property (class, copy, nullable) NSString *accessToken;
 
 @end