diff --git a/modules/ui/layers.js b/modules/ui/layers.js
index 4ab03365..19c05a6f 100644
--- a/modules/ui/layers.js
+++ b/modules/ui/layers.js
@@ -165,7 +165,7 @@ function drawHeightmap() {
     paths[h] += round(lineGen(points));
   }
 
-  terrs.append("rect").attr("x", 0).attr("y", 0).attr("width", "100%").attr("height", "100%").attr("fill", scheme(.8)); // draw base layer
+  terrs.append("rect").attr("x", 0).attr("y", 0).attr("width", graphWidth).attr("height", graphHeight).attr("fill", scheme(.8)); // draw base layer
   for (const i of d3.range(20, 101)) {
     if (paths[i].length < 10) continue;
     const color = getColor(i, scheme);