diff --git a/README.md b/README.md
index ca42725..6422623 100644
--- a/README.md
+++ b/README.md
@@ -28,7 +28,7 @@ cp config.example.toml config.toml
       download-ci-llvm = false
 ./x build library
 ./x build --stage 2 compiler/rustc
-./x build --target x86_64-unknown-linux-gnu,mips-zkm-zkvm-elf
+BOOTSTRAP_SKIP_TARGET_SANITY=1 ./x build --target x86_64-unknown-linux-gnu,mips-zkm-zkvm-elf
 BOOTSTRAP_SKIP_TARGET_SANITY=1 ./x install --target x86_64-unknown-linux-gnu,mips-zkm-zkvm-elf
 ```