diff --git a/basis/unix/debugger/debugger.factor b/basis/unix/debugger/debugger.factor
index 713c2202d4..ea32657057 100644
--- a/basis/unix/debugger/debugger.factor
+++ b/basis/unix/debugger/debugger.factor
@@ -1,6 +1,6 @@
 ! Copyright (C) 2008 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: debugger prettyprint accessors io ;
+USING: debugger prettyprint accessors unix io kernel ;
 IN: unix.debugger
 
 M: unix-error error.