diff --git a/modules/nativeHistory.js b/modules/nativeHistory.js
index 02e49fd..78e7470 100644
--- a/modules/nativeHistory.js
+++ b/modules/nativeHistory.js
@@ -18,6 +18,13 @@ import type {
 
 const { PUSH: HISTORY_PUSH, REPLACE: HISTORY_REPLACE } = Actions;
 
+/**
+ * This enhances a given history 
+ * (see https://github.com/ReactJSTraining/history/blob/master/docs/Glossary.md#createhistoryenhancer )
+ * by adding the methods `create(Pop|TransitionTo|Push|Replace)`. 
+ * These are used in RouterContext::getChildContext to produce the actual methods (`pop`, `transitionTo` etc.)
+ * with closured information about the current routing state (e.g. the current `navigationState` or `location`)
+ */
 const useNavState = (createHistory: Function) => (options = {}) => {
   const {
     replace: baseReplace,