diff --git a/lib/codegen/src/write.rs b/lib/codegen/src/write.rs
index 2e9faf6b40..0c3b7cbae9 100644
--- a/lib/codegen/src/write.rs
+++ b/lib/codegen/src/write.rs
@@ -10,6 +10,7 @@ use isa::{RegInfo, TargetIsa};
 use packed_option::ReservedValue;
 use std::fmt::{self, Write};
 use std::string::String;
+use std::vec::Vec;
 
 /// A `FuncWriter` used to decorate functions during printing.
 pub trait FuncWriter {