diff --git a/web/gui2-topo-lib/projects/gui2-topo-lib/src/lib/topology/topology.component.spec.ts b/web/gui2-topo-lib/projects/gui2-topo-lib/src/lib/topology/topology.component.spec.ts
index 0492858..bc3fd76 100644
--- a/web/gui2-topo-lib/projects/gui2-topo-lib/src/lib/topology/topology.component.spec.ts
+++ b/web/gui2-topo-lib/projects/gui2-topo-lib/src/lib/topology/topology.component.spec.ts
@@ -120,6 +120,7 @@
 
 class MockTrafficService {
     init(force: ForceSvgComponent) {}
+    destroy() {}
 }
 
 class MockLayoutService {}