Import prelude types explicitly from alloc
diff --git a/src/symbols/rust_string.rs b/src/symbols/rust_string.rs
index 67c53e1..774b824 100644
--- a/src/symbols/rust_string.rs
+++ b/src/symbols/rust_string.rs
@@ -1,3 +1,5 @@
+use alloc::borrow::ToOwned;
+use alloc::string::String;
 use core::mem::{ManuallyDrop, MaybeUninit};
 use core::ptr;
 use core::slice;