diff --git a/src/comp/back/rpath.rs b/src/comp/back/rpath.rs
index a2513649e942..66a632d61f76 100644
--- a/src/comp/back/rpath.rs
+++ b/src/comp/back/rpath.rs
@@ -9,6 +9,8 @@ import metadata::cstore;
 import driver::session;
 import util::filesearch;
 
+// FIXME #721: Despite the compiler warning, test does exist and needs
+// to be exported
 export get_rpath_flags, test;
 
 #[cfg(target_os="linux")]