diff --git a/README.md b/README.md
index f5e8d12..b9a76e0 100644
--- a/README.md
+++ b/README.md
@@ -36,7 +36,7 @@ sudo apt install cargo -y
 
 8. Disable build Rust
 ```bash
-export CRYPTOGRAPHY_DONT_BUILD_RUST=
+export CRYPTOGRAPHY_DONT_BUILD_RUST=1
 ```
 
 9. Install dependencies