diff --git a/compiler/tests-common/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTest.java b/compiler/tests-common/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTest.kt
similarity index 100%
rename from compiler/tests-common/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTest.java
rename to compiler/tests-common/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTest.kt
diff --git a/compiler/tests-common/org/jetbrains/kotlin/checkers/BaseDiagnosticsTest.java b/compiler/tests-common/org/jetbrains/kotlin/checkers/BaseDiagnosticsTest.kt
similarity index 100%
rename from compiler/tests-common/org/jetbrains/kotlin/checkers/BaseDiagnosticsTest.java
rename to compiler/tests-common/org/jetbrains/kotlin/checkers/BaseDiagnosticsTest.kt
diff --git a/compiler/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.java b/compiler/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.kt
similarity index 100%
rename from compiler/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.java
rename to compiler/tests/org/jetbrains/kotlin/checkers/AbstractDiagnosticsTestWithJsStdLib.kt