diff --git a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
index 7d2b5fb59a1..0141b0fa84f 100644
--- a/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
+++ b/libraries/tools/kotlin-gradle-plugin/src/main/kotlin/org/jetbrains/kotlin/gradle/targets/js/testing/karma/KotlinKarma.kt
@@ -384,6 +384,7 @@ class KotlinKarma(override val compilation: KotlinJsCompilation) : KotlinJsTestF
                     body()
 
                     if (isLaunchFailed) {
+                        showSuppressedOutput()
                         throw IllegalStateException("Launch of some browsers was failed")
                     }
                 }