Inheritance of Kotlin sealed interface/class from Java

Reports attempts to inherit from Kotlin sealed interfaces or classes in Java code.

Example:

// Kotlin file: MathExpression.kt

sealed class MathExpression

data class Const(val number: Double) : MathExpression()
data class Sum(val e1: MathExpression, val e2: MathExpression) : MathExpression()

// Java file: NotANumber.java

public class NotANumber extends MathExpression {
}

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

KotlinSealedInheritorsInJava

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Kotlin | Java interop issues

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection KotlinSealedInheritorsInJava

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025