diff --git a/src/main/java/pl/project13/janbanery/core/dao/SubTasksOf.java b/src/main/java/pl/project13/janbanery/core/dao/SubTasksOf.java
index <HASH>..<HASH> 100644
--- a/src/main/java/pl/project13/janbanery/core/dao/SubTasksOf.java
+++ b/src/main/java/pl/project13/janbanery/core/dao/SubTasksOf.java
@@ -17,8 +17,11 @@
 package pl.project13.janbanery.core.dao;
 
 import pl.project13.janbanery.core.flow.batch.SubTasksFlow;
+import pl.project13.janbanery.resources.SubTask;
 import pl.project13.janbanery.resources.Task;
 
+import java.io.IOException;
+
 /**
  * @author Konrad Malawski
  */
@@ -31,4 +34,6 @@ public interface SubTasksOf {
    * @return ready to work SubTasks instance
    */
   SubTasksFlow of(Task task);
+
+  void delete(SubTask subTask) throws IOException;
 }
added already implemented part to SubTasksOf.java interface, it's well usable here