diff --git a/collects/mrlib/cache-image-snip.ss b/collects/mrlib/cache-image-snip.ss
index 3147e0c6..66f52b90 100644
--- a/collects/mrlib/cache-image-snip.ss
+++ b/collects/mrlib/cache-image-snip.ss
@@ -132,7 +132,7 @@
                                   py)))])
           (send f put str)))
       
-      (define/override (get-num-scroll-steps) (+ (quotient height 20) 1))
+      (define/override (get-num-scroll-steps) (inexact->exact (+ (quotient height 20) 1)))
       (define/override (find-scroll-step y) (inexact->exact (floor (/ y 20))))
       (define/override (get-scroll-step-offset offset) (* offset 20))