diff --git a/src/samplesrc/rogue.pla b/src/samplesrc/rogue.pla
index 46ef793..c7f881b 100755
--- a/src/samplesrc/rogue.pla
+++ b/src/samplesrc/rogue.pla
@@ -187,7 +187,7 @@ def drawmap(xorg, yorg, dir, light)
   if light
     xmap = xorg - xcentr
     if xmap < 0
-      l    = mapcols + xmap
+      l    = mapcols - 1
       xscr = -xmap
       xmap = 0
     else