diff --git a/core/src/main/java/com/google/adk/apps/App.java b/core/src/main/java/com/google/adk/apps/App.java
index 897e24490..a087b738c 100644
--- a/core/src/main/java/com/google/adk/apps/App.java
+++ b/core/src/main/java/com/google/adk/apps/App.java
@@ -64,7 +64,7 @@ public BaseAgent rootAgent() {
     return rootAgent;
   }
 
-  public ImmutableList<? extends Plugin> plugins() {
+  public List<? extends Plugin> plugins() {
     return plugins;
   }