diff --git a/modules/extensions/src/terrain/terrain-pass.ts b/modules/extensions/src/terrain/terrain-pass.ts
index ca99999bca7..f4da18922c1 100644
--- a/modules/extensions/src/terrain/terrain-pass.ts
+++ b/modules/extensions/src/terrain/terrain-pass.ts
@@ -70,6 +70,7 @@ export class TerrainPass extends LayersPass {
     withParameters(
       this.gl,
       {
+        clearColor: [0, 0, 0, 0],
         depthTest: false
       },
       () =>