diff --git a/README.md b/README.md
index 4896e22..249d587 100644
--- a/README.md
+++ b/README.md
@@ -505,4 +505,4 @@ for (int level = 0; level <= max_level_with_files; level++) {
     TEST_CompactRange(level, begin, end);
   }
 ```
-
+Related Pr : [avoid lose efficacy for CompactRange by demiaowu · Pull Request #502 · google/leveldb](https://github.com/google/leveldb/pull/502)