diff --git a/collects/mred/private/wx/cocoa/queue.rkt b/collects/mred/private/wx/cocoa/queue.rkt
index a66bf5d9..97cb733b 100644
--- a/collects/mred/private/wx/cocoa/queue.rkt
+++ b/collects/mred/private/wx/cocoa/queue.rkt
@@ -391,4 +391,4 @@
   (post-dummy-event) ; why do we need this? 'nextEventMatchingMask:' seems to hang if we don't use it
   (set-ffi-obj! 'scheme_sleep #f _pointer (function-ptr sleep-until-event 
                                                         (_fun #:atomic? #t 
-                                                              _float _pointer -> _void))))
+                                                              _float _gcpointer -> _void))))
diff --git a/collects/mred/private/wx/common/queue.rkt b/collects/mred/private/wx/common/queue.rkt
index 010211ef..e89ef6fb 100644
--- a/collects/mred/private/wx/common/queue.rkt
+++ b/collects/mred/private/wx/common/queue.rkt
@@ -66,7 +66,7 @@
 
 (define-mz scheme_add_evt (_fun _Scheme_Type
                                 (_fun #:atomic? #t _scheme -> _int)
-                                (_fun #:atomic? #t _scheme _pointer -> _void)
+                                (_fun #:atomic? #t _scheme _gcpointer -> _void)
                                 _pointer
                                 _int
                                 -> _void))
@@ -189,7 +189,7 @@
                                           _racket _racket -> _void)
                                     _racket ; data
                                     _int ; strong?
-                                    -> _pointer))
+                                    -> _gcpointer))
 
 (define (shutdown-eventspace! e ignored)
   ;; atomic mode
diff --git a/collects/mred/private/wx/gtk/queue.rkt b/collects/mred/private/wx/gtk/queue.rkt
index 110e8932..766176e7 100644
--- a/collects/mred/private/wx/gtk/queue.rkt
+++ b/collects/mred/private/wx/gtk/queue.rkt
@@ -118,10 +118,10 @@
 (define POLLERR #x8)
 (define POLLHUP #x10)
 
-(define-mz scheme_get_fdset (_fun _pointer _int -> _pointer))
-(define-mz scheme_fdset (_fun _pointer _int -> _void))
-(define-mz scheme_set_wakeup_time (_fun _pointer _double -> _void))
-(define-mz scheme_add_fd_eventmask (_fun _pointer _int -> _void)
+(define-mz scheme_get_fdset (_fun _pointer _int -> _gcpointer))
+(define-mz scheme_fdset (_fun _gcpointer _int -> _void))
+(define-mz scheme_set_wakeup_time (_fun _gcpointer _double -> _void))
+(define-mz scheme_add_fd_eventmask (_fun _gcpointer _int -> _void)
   #:fail #f)
 
 (define (install-wakeup fds)