diff --git a/src/librustc_span/lib.rs b/src/librustc_span/lib.rs
index 060ad604369fb..dd7ba5cb6fc0c 100644
--- a/src/librustc_span/lib.rs
+++ b/src/librustc_span/lib.rs
@@ -14,6 +14,10 @@
 #![feature(optin_builtin_traits)]
 #![feature(specialization)]
 
+// FIXME(#56935): Work around ICEs during cross-compilation.
+#[allow(unused)]
+extern crate rustc_macros;
+
 use rustc_data_structures::AtomicRef;
 use rustc_macros::HashStable_Generic;
 use rustc_serialize::{Decodable, Decoder, Encodable, Encoder};