1diff --git b/src/untrusted.rs a/src/untrusted.rs
2index 010b001..47c281e 100644
3--- b/src/untrusted.rs
4+++ a/src/untrusted.rs
5@@ -105,6 +105,10 @@
6 #![allow(rustdoc::bare_urls)]
7 #![no_std]
8
9+// ANDROID: use std to allow building as a dylib.
10+#[cfg(android_dylib)]
11+extern crate std;
12+
13 /// A wrapper around `&'a [u8]` that helps in writing panic-free code.
14 ///
15 /// No methods of `Input` will ever panic.
16