diff --git a/index.js b/index.js
index 58f330b..651a3cf 100644
--- a/index.js
+++ b/index.js
@@ -169,7 +169,7 @@ class RustPlugin {
       "bootstrap",
       readFileSync(path.join(sourceDir, binary)),
       "",
-      0o755
+      "755"
     );
     const targetDir = this.localArtifactDir(profile);
     try {