diff --git a/basis/debugger/debugger.factor b/basis/debugger/debugger.factor
index a48cc89225..3b75c1e7a0 100644
--- a/basis/debugger/debugger.factor
+++ b/basis/debugger/debugger.factor
@@ -1,12 +1,12 @@
 ! Copyright (C) 2004, 2010 Slava Pestov.
 ! See http://factorcode.org/license.txt for BSD license.
-USING: slots arrays definitions generic hashtables summary io kernel
-math namespaces make prettyprint prettyprint.config sequences assocs
-sequences.private strings io.styles io.pathnames vectors words system
-splitting math.parser classes.mixin classes.tuple continuations
-continuations.private combinators generic.math classes.builtin classes
-compiler.units generic.standard generic.single vocabs init
-kernel.private io.encodings accessors math.order destructors
+USING: slots alien.c-types arrays definitions generic hashtables
+summary io kernel math namespaces make prettyprint prettyprint.config
+sequences assocs sequences.private strings io.styles io.pathnames
+vectors words system splitting math.parser classes.mixin classes.tuple
+continuations continuations.private combinators generic.math
+classes.builtin classes compiler.units generic.standard generic.single
+vocabs init kernel.private io.encodings accessors math.order destructors
 source-files parser classes.tuple.parser effects.parser lexer
 generic.parser strings.parser vocabs.loader vocabs.parser
 source-files.errors ;
@@ -347,6 +347,8 @@ M: wrong-values summary drop "Quotation's stack effect does not match call site"
 
 M: stack-effect-omits-dashes summary drop "Stack effect must contain “--”" ;
 
+M: no-c-type summary name>> unparse "“" "” is not a C type" surround ;
+
 {
     { [ os windows? ] [ "debugger.windows" require ] }
     { [ os unix? ] [ "debugger.unix" require ] }