diff --git a/htdp-lib/2htdp/private/world.rkt b/htdp-lib/2htdp/private/world.rkt
index 73529c64..28222173 100644
--- a/htdp-lib/2htdp/private/world.rkt
+++ b/htdp-lib/2htdp/private/world.rkt
@@ -258,8 +258,8 @@
                (style '(no-hscroll no-vscroll))
                (horizontal-inset INSET)
                (vertical-inset INSET)))
-        (send editor-canvas min-client-width (+ width INSET INSET))
-        (send editor-canvas min-client-height (+ height INSET INSET))
+        (send editor-canvas min-client-width (sub1 (+ width INSET INSET)))
+        (send editor-canvas min-client-height (sub1 (+ height INSET INSET)))
         (set!-values (enable-images-button disable-images-button)
                      (inner (values void void) create-frame/universe frame play-back:cust))
         (send editor-canvas focus)