Import from libcore where possible
diff --git a/src/rust_vec.rs b/src/rust_vec.rs
index 6f1d567..3ae5d5e 100644
--- a/src/rust_vec.rs
+++ b/src/rust_vec.rs
@@ -1,5 +1,5 @@
 use crate::rust_string::RustString;
-use std::mem::ManuallyDrop;
+use core::mem::ManuallyDrop;
 
 #[repr(C)]
 pub struct RustVec<T> {