diff --git a/strategy/app.d b/strategy/app.d
index cc6cb84..ef3e518 100644
--- a/strategy/app.d
+++ b/strategy/app.d
@@ -1,6 +1,7 @@
 module strategy.app;
 
 import strategy.duck;
+import strategy.flybehavior;
 
 void main()
 {
@@ -11,4 +12,6 @@ void main()
     Duck model = new ModelDuck;
     model.performQuack();
     model.performFly();
+    model.setFlyBehavior(new FlyRocketPowered);
+    model.performFly();
 }
diff --git a/strategy/duck.d b/strategy/duck.d
index 4364422..60e963e 100644
--- a/strategy/duck.d
+++ b/strategy/duck.d
@@ -24,6 +24,16 @@ abstract class Duck
     {
         writeln("All ducks float, even decoys!");
     }
+
+    void setFlyBehavior(FlyBehavior fb)
+    {
+        flyBehavior = fb;
+    }
+
+    void setQuackBehavior(QuackBehavior qb)
+    {
+        quackBehavior = qb;
+    }
 }
 
 class MallardDuck : Duck