diff --git a/basis/struct-vectors/struct-vectors.factor b/basis/struct-vectors/struct-vectors.factor
index b29ab19e4d..5a0654ea16 100644
--- a/basis/struct-vectors/struct-vectors.factor
+++ b/basis/struct-vectors/struct-vectors.factor
@@ -1,6 +1,6 @@
 ! Copyright (C) 2009 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: accessors byte-arrays growable kernel math sequences
+USING: accessors alien.c-types byte-arrays growable kernel math sequences
 sequences.private struct-arrays ;
 IN: struct-vectors