diff --git a/python/educational-core/src/com/jetbrains/edu/learning/StudySerializationUtils.java b/python/educational-core/src/com/jetbrains/edu/learning/StudySerializationUtils.java
index 21211d9c7dc6..a43254bc7a79 100644
--- a/python/educational-core/src/com/jetbrains/edu/learning/StudySerializationUtils.java
+++ b/python/educational-core/src/com/jetbrains/edu/learning/StudySerializationUtils.java
@@ -594,7 +594,7 @@ public class StudySerializationUtils {
       }
     }
 
-    private static void removeIndexFromSubtaskInfos(JsonObject placeholderObject) {
+    public static void removeIndexFromSubtaskInfos(JsonObject placeholderObject) {
       JsonArray infos = placeholderObject.getAsJsonArray(SUBTASK_INFOS);
       Map<Integer, JsonObject> objectsToInsert = new HashMap<>();
       for (JsonElement info : infos) {
diff --git a/python/educational-core/testSrc/com/jetbrains/edu/learning/stepic/StudyStepicFormatTest.java b/python/educational-core/testSrc/com/jetbrains/edu/learning/stepic/StudyStepicFormatTest.java
index ba0e7fb7e77a..46d4086bc631 100644
--- a/python/educational-core/testSrc/com/jetbrains/edu/learning/stepic/StudyStepicFormatTest.java
+++ b/python/educational-core/testSrc/com/jetbrains/edu/learning/stepic/StudyStepicFormatTest.java
@@ -2,6 +2,8 @@ package com.jetbrains.edu.learning.stepic;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonParser;
 import com.intellij.openapi.util.io.FileUtil;
 import com.intellij.util.containers.ContainerUtil;
 import com.jetbrains.edu.learning.StudySerializationUtils;
@@ -77,7 +79,9 @@ public class StudyStepicFormatTest {
     answerPlaceholder.setSubtaskInfos(ContainerUtil.newHashMap(ContainerUtil.list(0, 1), ContainerUtil.list(info1, info2)));
     final String placeholderSerialization = gson.toJson(answerPlaceholder);
     String expected = FileUtil.loadFile(new File(getTestDataPath(), "placeholder.json"));
-    assertEquals(expected, placeholderSerialization);
+    JsonObject object = new JsonParser().parse(expected).getAsJsonObject();
+    StudySerializationUtils.Json.removeIndexFromSubtaskInfos(object);
+    assertEquals(gson.toJson(gson.fromJson(object, AnswerPlaceholder.class)), placeholderSerialization);
 
   }