diff --git a/README.md b/README.md
index 693230e..b411d1a 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,7 @@
 
 ## Building
 
-- Place private key in `main/resources`
+- Place private key in `main/resources` (JSON/Array format, generated by solana-keygen)
 - Set `application.endpoint` (RPC) & `application.privateKey` (file name) in application.properties
 
 - `docker build .`