diff --git a/packages/grpc-js/src/filter-stack.ts b/packages/grpc-js/src/filter-stack.ts
index 622f3dd0..4733c821 100644
--- a/packages/grpc-js/src/filter-stack.ts
+++ b/packages/grpc-js/src/filter-stack.ts
@@ -89,7 +89,7 @@ export class FilterStackFactory implements FilterFactory<FilterStack> {
   }
 
   clone(): FilterStackFactory {
-    return new FilterStackFactory(this.factories);
+    return new FilterStackFactory([...this.factories]);
   }
 
   createFilter(): FilterStack {