diff --git a/collects/mred/private/wx/gtk/canvas.rkt b/collects/mred/private/wx/gtk/canvas.rkt
index 6ad214ca9b..b32b2dbee7 100644
--- a/collects/mred/private/wx/gtk/canvas.rkt
+++ b/collects/mred/private/wx/gtk/canvas.rkt
@@ -20,6 +20,8 @@
 
 (define-gtk gtk_drawing_area_new (_fun -> _GtkWidget))
 
+(define-gtk gtk_widget_queue_draw (_fun _GtkWidget -> _void))
+
 (define-gtk gtk_hbox_new (_fun _gboolean _int -> _GtkWidget))
 (define-gtk gtk_hscrollbar_new (_fun _pointer -> _GtkWidget))
 (define-gtk gtk_vscrollbar_new (_fun _pointer -> _GtkWidget))
@@ -169,6 +171,9 @@
 
     (define/public (on-paint) (void))
 
+    (define/override (refresh)
+      (gtk_widget_queue_draw client-gtk))
+
     (define/override (internal-on-client-size w h)
       (send dc reset-dc-size))
 
diff --git a/collects/racket/draw/bitmap-dc.rkt b/collects/racket/draw/bitmap-dc.rkt
index c4dc8cc441..066f3d98aa 100644
--- a/collects/racket/draw/bitmap-dc.rkt
+++ b/collects/racket/draw/bitmap-dc.rkt
@@ -40,7 +40,6 @@
       (values (exact->inexact (send bm get-width))
               (exact->inexact (send bm get-height))))
 
-    (define last-y -1)
     (def/public (set-pixel [real? x][real? y][color% c])
       (let ([s (bytes 255 (color-red c) (color-green c) (color-blue c))])
         (set-argb-pixels x y 1 1 s)))
diff --git a/collects/racket/draw/dc.rkt b/collects/racket/draw/dc.rkt
index 4b0630c042..c5b9ff24b4 100644
--- a/collects/racket/draw/dc.rkt
+++ b/collects/racket/draw/dc.rkt
@@ -263,7 +263,7 @@
             [o2 (cairo_font_options_create)])
         (when o
           (cairo_font_options_copy o2 o))
-        (cairo_font_options_set_antialias 
+        (cairo_font_options_set_antialias
          o2 
          (case (dc-adjust-smoothing smoothing)
            [(default) CAIRO_ANTIALIAS_SUBPIXEL] ; should be DEFAULT?