diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/testing/TCServiceMessagesClient.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/testing/TCServiceMessagesClient.kt
index 75ee0005d5d..b3f565f8dbe 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/testing/TCServiceMessagesClient.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/internal/testing/TCServiceMessagesClient.kt
@@ -154,12 +154,13 @@ internal open class TCServiceMessagesClient(
 
         val parsedStackTrace = settings.stackTraceParser(stacktrace)
 
+        val failMessage = parsedStackTrace?.message ?: message.failureMessage
         results.failure(
             descriptor.id,
             KotlinTestFailure(
-                (parsedStackTrace?.message ?: message.failureMessage)?.let { extractExceptionClassName(it) }
+                failMessage?.let { extractExceptionClassName(it) }
                     ?: "Unknown",
-                message.failureMessage,
+                failMessage,
                 stacktrace,
                 patchStackTrace(this, parsedStackTrace?.stackTrace),
                 message.expected,
diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/testing/KotlinTestFailure.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/testing/KotlinTestFailure.kt
index 1be7fca5366..0faad3e8440 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/testing/KotlinTestFailure.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/testing/KotlinTestFailure.kt
@@ -19,7 +19,7 @@ import org.gradle.internal.serialize.PlaceholderException
 class KotlinTestFailure(
     className: String,
     message: String?,
-    val stackTraceString: String?,
+    private val stackTraceString: String?,
     private val stackTrace: List<StackTraceElement>? = null,
     val expected: String? = null,
     val actual: String? = null
@@ -38,9 +38,10 @@ class KotlinTestFailure(
         return this
     }
 
-    override fun toString(): String =
-        if (stackTraceString != null) {
+    override fun toString(): String {
+        return if (stackTraceString != null) {
             if (message != null && message!! !in stackTraceString) message + "\n" + stackTraceString
             else stackTraceString
         } else message ?: "Test failed"
+    }
 }
\ No newline at end of file