diff --git a/basis/specialized-arrays/specialized-arrays.factor b/basis/specialized-arrays/specialized-arrays.factor
index 992dbac6d6..97ce2ed1ff 100644
--- a/basis/specialized-arrays/specialized-arrays.factor
+++ b/basis/specialized-arrays/specialized-arrays.factor
@@ -116,7 +116,8 @@ M: A v*high [ * \ T heap-size neg shift ] 2map ; inline
 
 ;FUNCTOR
 
-: underlying-type ( c-type -- c-type' )
+GENERIC: underlying-type ( c-type -- c-type' )
+M: c-type-word underlying-type
     dup "c-type" word-prop {
         { [ dup not ] [ drop no-c-type ] }
         { [ dup pointer? ] [ 2drop void* ] }
@@ -124,6 +125,9 @@ M: A v*high [ * \ T heap-size neg shift ] 2map ; inline
         [ drop ]
     } cond ;
 
+M: pointer underlying-type
+    drop void* ;
+
 : specialized-array-vocab ( c-type -- vocab )
     [
         "specialized-arrays.instances." %