diff --git a/basis/alien/debugger/debugger.factor b/basis/alien/debugger/debugger.factor
index 4ac3174bb7..a04697155e 100644
--- a/basis/alien/debugger/debugger.factor
+++ b/basis/alien/debugger/debugger.factor
@@ -1,6 +1,7 @@
 ! Copyright (C) 2010 Joe Groff.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: ;
+USING: alien.c-types alien.parser summary sequences accessors
+prettyprint ;
 IN: alien.debugger
 
 M: no-c-type summary name>> unparse "“" "” is not a C type" surround ;