1diff --git a/src/lib.rs b/src/lib.rs
2index 3d4d185..9081ecf 100644
3--- a/src/lib.rs
4+++ b/src/lib.rs
5@@ -1,3 +1,4 @@
6+extern crate proc_macro;
7 use proc_macro::TokenStream;
8 use proc_macro2::{Delimiter, Group, TokenStream as TokenStream2, TokenTree};
9 use quote::quote;
10