diff --git a/fcore/text-scroll.sml b/fcore/text-scroll.sml
index fb8dfef..3807921 100644
--- a/fcore/text-scroll.sml
+++ b/fcore/text-scroll.sml
@@ -15,6 +15,7 @@ struct
           val howManyColumnsCanWeFit =
             if windowWidth >= TC.textLineWidth then TC.textLineCount
             else windowWidth div TC.xSpace
+          val howManyColumnsCanWeFit = howManyColumnsCanWeFit - 1
         in
           if columnDifference < howManyColumnsCanWeFit then 0
           else columnDifference - howManyColumnsCanWeFit