diff --git a/src/cmp/cmpbackend-cxx/cmpc-mach.lsp b/src/cmp/cmpbackend-cxx/cmpc-mach.lsp
index ad4794e158a0552d2834e5839195ee96797b4f69..0e0dae15369456ee811df3d958335e8540e50f6b 100644
--- a/src/cmp/cmpbackend-cxx/cmpc-mach.lsp
+++ b/src/cmp/cmpbackend-cxx/cmpc-mach.lsp
@@ -38,12 +38,20 @@
 (defun host-type-record (host-type)
   (ext:if-let ((record (gethash host-type (machine-host-type-hash *machine*))))
     record
-    (cmperr "Not a valid C type name ~A" host-type)))
+    (if ffi::*ffi-types*
+	(let ((ffi-type (gethash host-type ffi::*ffi-types*)))
+	  (if ffi-type
+	      (host-type-record ffi-type)
+	      (cmperr "Not a valid FFI type name ~A" host-type)))
+	(cmperr "Not a valid C type name ~A" host-type))))
+
 
 (defun host-type->lisp-type (name)
-  (let ((output (host-type-record-unsafe name)))
-    (cond (output
-           (host-type-lisp-type output))
+  (let ((output (host-type-record-unsafe name))
+        (ffi-type (when ffi::*ffi-types*
+                    (gethash name ffi::*ffi-types*))))
+    (cond (output (host-type-lisp-type output))
+          (ffi-type (host-type->lisp-type ffi-type))
           ((lisp-type-p name) name)
           (t (error "Unknown representation type ~S" name)))))