diff --git a/component/viewer/src/main/java/one/nem/lacerta/component/viewer/ItemClickListener.java b/component/viewer/src/main/java/one/nem/lacerta/component/viewer/ItemClickListener.java
index 91026a39..02cbae6e 100644
--- a/component/viewer/src/main/java/one/nem/lacerta/component/viewer/ItemClickListener.java
+++ b/component/viewer/src/main/java/one/nem/lacerta/component/viewer/ItemClickListener.java
@@ -2,4 +2,6 @@ package one.nem.lacerta.component.viewer;
 
 public interface ItemClickListener {
     void onItemClick(String fileName); // DEBUG
+
+    void onItemLongClick(String fileName, int position);
 }