diff --git a/platform/external-system-api/api-dump-unreviewed.txt b/platform/external-system-api/api-dump-unreviewed.txt
index a9b819695f5e..17e734f6862c 100644
--- a/platform/external-system-api/api-dump-unreviewed.txt
+++ b/platform/external-system-api/api-dump-unreviewed.txt
@@ -937,10 +937,10 @@ c:com.intellij.openapi.externalSystem.model.task.event.Failure
 - f:getCauses():java.util.List
 - f:getDescription():java.lang.String
 - f:getMessage():java.lang.String
-c:com.intellij.openapi.externalSystem.model.task.event.FailureResult
+f:com.intellij.openapi.externalSystem.model.task.event.FailureResult
 - com.intellij.openapi.externalSystem.model.task.event.OperationResult
 - <init>(J,J,java.util.List):V
-- getFailures():java.util.List
+- f:getFailures():java.util.List
 c:com.intellij.openapi.externalSystem.model.task.event.OperationDescriptor
 - java.io.Serializable
 - <init>(java.lang.String,J):V
@@ -951,15 +951,15 @@ c:com.intellij.openapi.externalSystem.model.task.event.OperationDescriptor
 c:com.intellij.openapi.externalSystem.model.task.event.OperationResult
 - java.io.Serializable
 - <init>(J,J):V
-- getEndTime():J
-- getStartTime():J
-c:com.intellij.openapi.externalSystem.model.task.event.SkippedResult
+- f:getEndTime():J
+- f:getStartTime():J
+f:com.intellij.openapi.externalSystem.model.task.event.SkippedResult
 - com.intellij.openapi.externalSystem.model.task.event.OperationResult
 - <init>(J,J):V
-c:com.intellij.openapi.externalSystem.model.task.event.SuccessResult
+f:com.intellij.openapi.externalSystem.model.task.event.SuccessResult
 - com.intellij.openapi.externalSystem.model.task.event.OperationResult
 - <init>(J,J,Z):V
-- isUpToDate():Z
+- f:isUpToDate():Z
 f:com.intellij.openapi.externalSystem.model.task.event.TaskOperationDescriptor
 - com.intellij.openapi.externalSystem.model.task.event.OperationDescriptor
 - <init>(java.lang.String,J,java.lang.String):V
diff --git a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/FailureResult.java b/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/FailureResult.java
deleted file mode 100644
index c9dfd032d561..000000000000
--- a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/FailureResult.java
+++ /dev/null
@@ -1,35 +0,0 @@
-/*
- * Copyright 2000-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.intellij.openapi.externalSystem.model.task.event;
-
-import java.util.List;
-
-/**
- * @author Vladislav.Soroka
- */
-public class FailureResult extends OperationResult {
-
-  private final List<? extends Failure> myFailures;
-
-  public FailureResult(long startTime, long endTime, List<? extends Failure> failures) {
-    super(startTime, endTime);
-    myFailures = failures;
-  }
-
-  public List<? extends Failure> getFailures() {
-    return myFailures;
-  }
-}
diff --git a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/OperationResult.java b/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/OperationResult.java
deleted file mode 100644
index 46c89128aa21..000000000000
--- a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/OperationResult.java
+++ /dev/null
@@ -1,26 +0,0 @@
-// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
-package com.intellij.openapi.externalSystem.model.task.event;
-
-import java.io.Serializable;
-
-/**
- * @author Vladislav.Soroka
- */
-public class OperationResult implements Serializable {
-
-  private final long myStartTime;
-  private final long myEndTime;
-
-  public OperationResult(long startTime, long endTime) {
-    myStartTime = startTime;
-    myEndTime = endTime;
-  }
-
-  public long getStartTime() {
-    return myStartTime;
-  }
-
-  public long getEndTime() {
-    return myEndTime;
-  }
-}
diff --git a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/SkippedResult.java b/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/SkippedResult.java
deleted file mode 100644
index f9fbab451682..000000000000
--- a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/SkippedResult.java
+++ /dev/null
@@ -1,26 +0,0 @@
-/*
- * Copyright 2000-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.intellij.openapi.externalSystem.model.task.event;
-
-/**
- * @author Vladislav.Soroka
- */
-public class SkippedResult extends OperationResult {
-
-  public SkippedResult(long startTime, long endTime) {
-    super(startTime, endTime);
-  }
-}
diff --git a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/SuccessResult.java b/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/SuccessResult.java
deleted file mode 100644
index 3258dbc73a57..000000000000
--- a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/SuccessResult.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright 2000-2015 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-package com.intellij.openapi.externalSystem.model.task.event;
-
-/**
- * @author Vladislav.Soroka
- */
-public class SuccessResult extends OperationResult {
-
-  private final boolean myUpToDate;
-
-  public SuccessResult(long startTime, long endTime, boolean isUpToDate) {
-    super(startTime, endTime);
-    myUpToDate = isUpToDate;
-  }
-
-  public boolean isUpToDate() {
-    return myUpToDate;
-  }
-}
\ No newline at end of file
diff --git a/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/operationResult.kt b/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/operationResult.kt
new file mode 100644
index 000000000000..fd08e9ebbb2d
--- /dev/null
+++ b/platform/external-system-api/src/com/intellij/openapi/externalSystem/model/task/event/operationResult.kt
@@ -0,0 +1,12 @@
+// Copyright 2000-2024 JetBrains s.r.o. and contributors. Use of this source code is governed by the Apache 2.0 license.
+package com.intellij.openapi.externalSystem.model.task.event
+
+import java.io.Serializable
+
+open class OperationResult(val startTime: Long, val endTime: Long) : Serializable
+
+class FailureResult(startTime: Long, endTime: Long, val failures: List<Failure>) : OperationResult(startTime = startTime, endTime = endTime)
+
+class SkippedResult(startTime: Long, endTime: Long) : OperationResult(startTime = startTime, endTime = endTime)
+
+class SuccessResult(startTime: Long, endTime: Long, val isUpToDate: Boolean) : OperationResult(startTime = startTime, endTime = endTime)
\ No newline at end of file