diff --git a/src/api.rs b/src/api.rs
index 8b91cd2a..852fd2a7 100644
--- a/src/api.rs
+++ b/src/api.rs
@@ -34,6 +34,7 @@ use crate::optimize::optimize_into_ast;
 use crate::stdlib::{
     any::{type_name, TypeId},
     boxed::Box,
+    string::ToString,
 };
 
 #[cfg(not(feature = "no_optimize"))]