diff --git a/README.md b/README.md
index d3ebb8e4..ae04f9a7 100644
--- a/README.md
+++ b/README.md
@@ -319,6 +319,7 @@ _Efficient and specific data structures._
 - [SBE](https://github.com/real-logic/simple-binary-encoding) - Simple Binary Encoding, one of the fastest message formats around.
 - [Tape](https://github.com/square/tape) - Lightning-fast, transactional, file-based FIFO.
 - [Wire](https://github.com/square/wire) - Clean, lightweight protocol buffers.
+- [Wormhole4j](https://github.com/komamitsu/wormhole4j) - High-performance sorted map with fast range scans and thread-safe concurrent access, based on the Wormhole index structure.
 
 ### Database