diff --git a/src/viewport-three/viewport-host.ts b/src/viewport-three/viewport-host.ts
index 392c00b3..b5b65d6f 100644
--- a/src/viewport-three/viewport-host.ts
+++ b/src/viewport-three/viewport-host.ts
@@ -2050,6 +2050,12 @@ export class ViewportHost {
     this.terrainBrushPreviewLine.material.dispose();
     this.terrainBrushPreviewCenter.geometry.dispose();
     this.terrainBrushPreviewCenter.material.dispose();
+    this.terrainGridResizeEdgeLine.geometry.dispose();
+    this.terrainGridResizeEdgeLine.material.dispose();
+    this.terrainGridResizeArrowLine.geometry.dispose();
+    this.terrainGridResizeArrowLine.material.dispose();
+    this.terrainGridResizeArrowHead.geometry.dispose();
+    this.terrainGridResizeArrowHead.material.dispose();
     this.environmentBlendCache.dispose();
     this.shaderSkyEnvironmentBlendCache.dispose();
     this.shaderSkyEnvironmentCache.dispose();