diff --git a/tools/src/main.rs b/tools/src/main.rs
index 1e907a2..deff263 100644
--- a/tools/src/main.rs
+++ b/tools/src/main.rs
@@ -107,7 +107,7 @@ fn main() {
                 methods: vec![],
                 return_type: None,
                 parameters: vec![path],
-                docstring: none,
+                docstring: None,
             });
         }
     }