diff --git a/app/views/export/start.rjs b/app/views/export/start.rjs
index 5e4a2b91c..1a157afca 100644
--- a/app/views/export/start.rjs
+++ b/app/views/export/start.rjs
@@ -140,7 +140,7 @@ page << <<EOJ
 
     $("mapnik_max_scale").innerHTML = roundScale(max_scale);
 
-    mapnikSizeChanged();
+    mapnikScaleChanged();
 
     for (var o = 0; o < $("osmarender_zoom").options.length; o++) {
       var option = $("osmarender_zoom").options[o];