diff --git a/collects/ffi/unsafe/objc.rkt b/collects/ffi/unsafe/objc.rkt
index 1166f80248..fa5c754fad 100644
--- a/collects/ffi/unsafe/objc.rkt
+++ b/collects/ffi/unsafe/objc.rkt
@@ -33,7 +33,9 @@
 (define _BOOL (make-ctype _byte
                           (lambda (v) (if v 1 0))
                           (lambda (v) (not (eq? v 0)))))
-(define _IMP (_fun _id _id -> _id))
+
+(define _Method (_cpointer/null 'Method))
+(define _IMP (_fun _id _SEL -> _id))
 
 (define-cstruct _objc_super ([receiver _id][class _Class]))
 
@@ -864,3 +866,10 @@
 
 (define (objc-is-a? v c)
   (ptr-equal? (object-get-class v) c))
+
+;; --------------------------------------------------
+
+(define-objc class_getInstanceMethod (_fun _Class _SEL -> _Method))
+(define-objc method_setImplementation (_fun _Method _IMP -> _IMP))
+
+
diff --git a/collects/mred/private/wx/cocoa/queue.rkt b/collects/mred/private/wx/cocoa/queue.rkt
index d6ca67c558..a66bf5d99a 100644
--- a/collects/mred/private/wx/cocoa/queue.rkt
+++ b/collects/mred/private/wx/cocoa/queue.rkt
@@ -29,9 +29,21 @@
  queue-event
  yield)
 
-(import-class NSApplication NSAutoreleasePool NSColor)
+(import-class NSApplication NSAutoreleasePool NSColor NSProcessInfo NSArray)
 (import-protocol NSApplicationDelegate)
 
+;; Extreme hackery to hide original arguments from
+;; NSApplication, because NSApplication wants to turn 
+;; the arguments into `application:openFile:' calls.
+;; To hide the arguments, we replace the implementation
+;; of `arguments' in the NSProcessInfo object.
+(define (hack-argument-replacement self method)
+  (tell NSArray 
+        arrayWithObjects: #:type (_vector i _NSString) (vector (path->string (find-system-path 'exec-file)))
+        count: #:type _NSUInteger 1))
+(let ([m (class_getInstanceMethod NSProcessInfo (selector arguments))])
+  (void (method_setImplementation m hack-argument-replacement)))
+
 (define app (tell NSApplication sharedApplication))
 
 (define-objc-class MyApplicationDelegate NSObject #:protocols (NSApplicationDelegate)