diff --git a/collects/mred/private/wx/cocoa/canvas.rkt b/collects/mred/private/wx/cocoa/canvas.rkt
index d8461e1f7d..c7c6989bce 100644
--- a/collects/mred/private/wx/cocoa/canvas.rkt
+++ b/collects/mred/private/wx/cocoa/canvas.rkt
@@ -371,7 +371,7 @@
               (tell (tell (if is-combo? RacketComboBox RacketView)
                           alloc)
                     initWithFrame: #:type _NSRect r)
-              (let* ([share-context (send gl-config get-share-context)]
+              (let* ([share-context (and gl-config (send gl-config get-share-context))]
                      [context-handle (and share-context (send share-context get-handle))]
                      [pf (gl-config->pixel-format gl-config)]
                      [new-context (and
diff --git a/collects/mred/private/wx/gtk/gl-context.rkt b/collects/mred/private/wx/gtk/gl-context.rkt
index 32d222a901..d2ee30c68b 100644
--- a/collects/mred/private/wx/gtk/gl-context.rkt
+++ b/collects/mred/private/wx/gtk/gl-context.rkt
@@ -148,7 +148,7 @@
 
 (define (prepare-widget-gl-context gtk config)
   (init!)
-  (let ([share-context (send config get-share-context)]
+  (let ([share-context (and config (send config get-share-context))]
         [config (config->GdkGLConfig #f ; (gtk_widget_get_screen gtk)
                                      (or config
                                          (new gl-config%))