diff --git a/.gitignore b/.gitignore
index 9586260879aa..3c15b4f439a0 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,3 +4,4 @@ cache
 unicorn
 unicorn2
 .*.swp
+venv
diff --git a/README.md b/README.md
index 2fd4d1a06850..698b75ca8f94 100644
--- a/README.md
+++ b/README.md
@@ -24,6 +24,10 @@ contracts -- A Merkleized MIPS processor on chain + the challenge logic
 
 ## Usage
 ```
+# build unicorn
+./build_unicorn.sh
+export LIBUNICORN_PATH=$(pwd)/unicorn2/
+
 # build minigeth for MIPS
 (cd mipigo && pip3 install -r requirements.txt && ./build.sh)