diff --git a/libraries/kotlin.test/js/build.gradle b/libraries/kotlin.test/js/build.gradle
index 9c194bc89c1..af894c221fa 100644
--- a/libraries/kotlin.test/js/build.gradle
+++ b/libraries/kotlin.test/js/build.gradle
@@ -17,6 +17,7 @@ compileKotlin2Js {
     kotlinOptions.freeCompilerArgs = [
             "-Xallow-kotlin-package",
             "-Xopt-in=kotlin.contracts.ExperimentalContracts",
+            "-Xopt-in=kotlin.RequiresOptIn",
     ]
     kotlinOptions {
         moduleKind = "umd"