diff --git a/contracts/integrations/test/actors/hybrids.ts b/contracts/integrations/test/actors/hybrids.ts
index 72e6c835e7..bd55763de8 100644
--- a/contracts/integrations/test/actors/hybrids.ts
+++ b/contracts/integrations/test/actors/hybrids.ts
@@ -2,4 +2,4 @@ import { Actor } from './base';
 import { MakerMixin } from './maker';
 import { PoolOperatorMixin } from './pool_operator';
 
-export const OperatorMaker = PoolOperatorMixin(MakerMixin(Actor));
+export class OperatorMaker extends PoolOperatorMixin(MakerMixin(Actor)) {}
diff --git a/contracts/integrations/test/actors/maker.ts b/contracts/integrations/test/actors/maker.ts
index 53853b4b08..870716c7d2 100644
--- a/contracts/integrations/test/actors/maker.ts
+++ b/contracts/integrations/test/actors/maker.ts
@@ -56,4 +56,4 @@ export function MakerMixin<TBase extends Constructor>(Base: TBase) {
     };
 }
 
-export const Maker = MakerMixin(Actor);
+export class Maker extends MakerMixin(Actor) {}
diff --git a/contracts/integrations/test/actors/pool_operator.ts b/contracts/integrations/test/actors/pool_operator.ts
index 6f58418960..3f15b8a002 100644
--- a/contracts/integrations/test/actors/pool_operator.ts
+++ b/contracts/integrations/test/actors/pool_operator.ts
@@ -63,4 +63,4 @@ export function PoolOperatorMixin<TBase extends Constructor>(Base: TBase) {
     };
 }
 
-export const PoolOperator = PoolOperatorMixin(Actor);
+export class PoolOperator extends PoolOperatorMixin(Actor) {}