diff --git a/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/CCCheckListener.java b/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/CCCheckListener.java
index a737551a5e9e..12aa92541496 100644
--- a/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/CCCheckListener.java
+++ b/python/educational-core/course-creator/src/com/jetbrains/edu/coursecreator/CCCheckListener.java
@@ -3,7 +3,7 @@ package com.jetbrains.edu.coursecreator;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.jetbrains.edu.learning.StudyCheckListener;
-import com.jetbrains.edu.learning.courseFormat.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.Task;
 import org.jetbrains.annotations.NotNull;
 
 public class CCCheckListener implements StudyCheckListener {
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/EduPluginConfigurator.java b/python/educational-core/student/src/com/jetbrains/edu/learning/EduPluginConfigurator.java
index b886a8587d10..da549bc885e8 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/EduPluginConfigurator.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/EduPluginConfigurator.java
@@ -16,7 +16,8 @@ import com.jetbrains.edu.learning.actions.*;
 import com.jetbrains.edu.learning.core.EduNames;
 import com.jetbrains.edu.learning.courseFormat.Course;
 import com.jetbrains.edu.learning.courseFormat.Lesson;
-import com.jetbrains.edu.learning.courseFormat.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.TaskWithSubtasks;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -72,7 +73,7 @@ public interface EduPluginConfigurator {
     return false;
   }
 
-  default void createTestsForNewSubtask(@NotNull Project project, @NotNull Task task) {}
+  default void createTestsForNewSubtask(@NotNull Project project, @NotNull TaskWithSubtasks task) {}
 
   /**
    * Used for code highlighting in Task Description tool window
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/StudyCheckListener.java b/python/educational-core/student/src/com/jetbrains/edu/learning/StudyCheckListener.java
index 7f12d4411c39..d4896f864d27 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/StudyCheckListener.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/StudyCheckListener.java
@@ -2,7 +2,7 @@ package com.jetbrains.edu.learning;
 
 import com.intellij.openapi.extensions.ExtensionPointName;
 import com.intellij.openapi.project.Project;
-import com.jetbrains.edu.learning.courseFormat.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.Task;
 import org.jetbrains.annotations.NotNull;
 
 public interface StudyCheckListener {
diff --git a/python/educational-core/student/src/com/jetbrains/edu/learning/StudyFileEditorManagerListener.java b/python/educational-core/student/src/com/jetbrains/edu/learning/StudyFileEditorManagerListener.java
index f92e351c4ddb..1eac1fb00a97 100644
--- a/python/educational-core/student/src/com/jetbrains/edu/learning/StudyFileEditorManagerListener.java
+++ b/python/educational-core/student/src/com/jetbrains/edu/learning/StudyFileEditorManagerListener.java
@@ -5,7 +5,8 @@ import com.intellij.openapi.fileEditor.FileEditorManagerEvent;
 import com.intellij.openapi.fileEditor.FileEditorManagerListener;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.vfs.VirtualFile;
-import com.jetbrains.edu.learning.courseFormat.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.ChoiceTask;
+import com.jetbrains.edu.learning.courseFormat.tasks.Task;
 import com.jetbrains.edu.learning.editor.StudyChoiceVariantsPanel;
 import com.jetbrains.edu.learning.ui.StudyToolWindow;
 import org.jetbrains.annotations.NotNull;
@@ -25,8 +26,8 @@ public class StudyFileEditorManagerListener implements FileEditorManagerListener
     Task task = getTask(file);
     setTaskText(task, StudyUtils.getTaskDir(file));
     if (task != null) {
-      if (task.isChoiceTask()) {
-        final StudyChoiceVariantsPanel choicePanel = new StudyChoiceVariantsPanel(task);
+      if (task instanceof ChoiceTask) {
+        final StudyChoiceVariantsPanel choicePanel = new StudyChoiceVariantsPanel((ChoiceTask)task);
         myToolWindow.setBottomComponent(choicePanel);
       }
       else {
diff --git a/python/educational-python/Edu-Python/src/com/jetbrains/edu/learning/PyEduPluginConfigurator.java b/python/educational-python/Edu-Python/src/com/jetbrains/edu/learning/PyEduPluginConfigurator.java
index daf622cba5c8..eee62abd65a9 100644
--- a/python/educational-python/Edu-Python/src/com/jetbrains/edu/learning/PyEduPluginConfigurator.java
+++ b/python/educational-python/Edu-Python/src/com/jetbrains/edu/learning/PyEduPluginConfigurator.java
@@ -18,7 +18,8 @@ import com.jetbrains.edu.coursecreator.settings.CCSettings;
 import com.jetbrains.edu.learning.actions.StudyCheckAction;
 import com.jetbrains.edu.learning.core.EduNames;
 import com.jetbrains.edu.learning.courseFormat.Course;
-import com.jetbrains.edu.learning.courseFormat.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.Task;
+import com.jetbrains.edu.learning.courseFormat.tasks.TaskWithSubtasks;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
@@ -79,7 +80,7 @@ public class PyEduPluginConfigurator implements EduPluginConfigurator {
   }
 
   @Override
-  public void createTestsForNewSubtask(@NotNull Project project, @NotNull Task task) {
+  public void createTestsForNewSubtask(@NotNull Project project, @NotNull TaskWithSubtasks task) {
     VirtualFile taskDir = task.getTaskDir(project);
     if (taskDir == null) {
       return;