format
diff --git a/rocketmq-rocksdb/README.md b/rocketmq-rocksdb/README.md
index 4dd9094..d0ddbb1 100644
--- a/rocketmq-rocksdb/README.md
+++ b/rocketmq-rocksdb/README.md
@@ -130,7 +130,8 @@
 
 
 ## Copy `librocksdbjni-win64.dll` to `rocksdbjni-x.y.z.jar`
-jar -uf rocksdbjni-x.y.z.jar librocksdbjni-win64.dll
+
+    jar -uf rocksdbjni-x.y.z.jar librocksdbjni-win64.dll
 
 Finally, we use the following file to release an official rocksdb release for rocketmq: