diff --git a/README.md b/README.md
index 7259f0b..119e4d2 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 FFI export of Ethereum's ecrecover
 
 prerequisite:
-- a checked out copy of parity-ethereum (https://github.com/paritytech/parity-ethereum) checked out in the same directory this is
+- a checked out copy of parity-ethereum (https://github.com/paritytech/parity-ethereum) checked out in the same directory this is (i.e. it will be references as `../parity-ethereum`)
 
 to compile:
 `cargo build`