diff --git a/src/rt/rustrt.def.in b/src/rt/rustrt.def.in
index d724dd714cf2..e378fa8dc442 100644
--- a/src/rt/rustrt.def.in
+++ b/src/rt/rustrt.def.in
@@ -31,6 +31,7 @@ str_from_buf
 str_from_cstr
 str_from_vec
 str_push_byte
+str_vec
 task_sleep
 unsupervise
 upcall_clone_chan