diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxedBasicValue.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxedBasicValue.kt
similarity index 100%
rename from compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxedBasicValue.java
rename to compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxedBasicValue.kt
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt
similarity index 100%
rename from compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.java
rename to compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/BoxingInterpreter.kt
diff --git a/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingInterpreter.java b/compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingInterpreter.kt
similarity index 100%
rename from compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingInterpreter.java
rename to compiler/backend/src/org/jetbrains/kotlin/codegen/optimization/boxing/RedundantBoxingInterpreter.kt