diff --git a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/FrameworkAdapter.kt b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/FrameworkAdapter.kt
index 6a4e401db93..a696603e8c7 100644
--- a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/FrameworkAdapter.kt
+++ b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/FrameworkAdapter.kt
@@ -38,5 +38,5 @@ public external interface FrameworkAdapter {
      * @param ignored whether the test is ignored
      * @param testFn contains test body invocation
      */
-    fun test(name: String, ignored: Boolean, testFn: () -> Any)
+    fun test(name: String, ignored: Boolean, testFn: () -> Any?)
 }
diff --git a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/BareAdapter.kt b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/BareAdapter.kt
index 760077b921a..bbaa8b0ec4c 100644
--- a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/BareAdapter.kt
+++ b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/BareAdapter.kt
@@ -18,7 +18,7 @@ internal open class BareAdapter : FrameworkAdapter {
         }
     }
 
-    override fun test(name: String, ignored: Boolean, testFn: () -> Any) {
+    override fun test(name: String, ignored: Boolean, testFn: () -> Any?) {
         if (!ignored) {
             testFn()
         }
diff --git a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/Externals.kt b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/Externals.kt
index 06d9af4393a..8bdc6071bc9 100644
--- a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/Externals.kt
+++ b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/Externals.kt
@@ -10,8 +10,8 @@ package kotlin.test.adapters
  */
 internal external object QUnit {
     fun module(name: String, suiteFn: () -> Unit): Unit
-    fun test(name: String, testFn: (dynamic) -> Any): Unit
-    fun skip(name: String, testFn: (dynamic) -> Any): Unit
+    fun test(name: String, testFn: (dynamic) -> Any?): Unit
+    fun skip(name: String, testFn: (dynamic) -> Any?): Unit
 }
 
 /*
@@ -20,8 +20,8 @@ internal external object QUnit {
 
 internal external fun describe(name: String, fn: () -> Unit)
 internal external fun xdescribe(name: String, fn: () -> Unit)
-internal external fun it(name: String, fn: () -> Any)
-internal external fun xit(name: String, fn: () -> Any)
+internal external fun it(name: String, fn: () -> Any?)
+internal external fun xit(name: String, fn: () -> Any?)
 
 internal fun isQUnit() = jsTypeOf(QUnit) !== "undefined"
 
diff --git a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/JasmineLikeAdapter.kt b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/JasmineLikeAdapter.kt
index bd4591747d8..40aecf648b2 100644
--- a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/JasmineLikeAdapter.kt
+++ b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/JasmineLikeAdapter.kt
@@ -20,7 +20,7 @@ internal class JasmineLikeAdapter : FrameworkAdapter {
         }
     }
 
-    override fun test(name: String, ignored: Boolean, testFn: () -> Any) {
+    override fun test(name: String, ignored: Boolean, testFn: () -> Any?) {
         if (ignored) {
             xit(name, testFn)
         } else {
diff --git a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/QUnitAdapter.kt b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/QUnitAdapter.kt
index 27957af8e2b..68feeaa217c 100644
--- a/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/QUnitAdapter.kt
+++ b/libraries/kotlin.test/js/src/main/kotlin/kotlin/test/adapters/QUnitAdapter.kt
@@ -22,7 +22,7 @@ internal class QUnitAdapter : FrameworkAdapter {
         ignoredSuite = prevIgnore
     }
 
-    override fun test(name: String, ignored: Boolean, testFn: () -> Any) {
+    override fun test(name: String, ignored: Boolean, testFn: () -> Any?) {
         if (ignored or ignoredSuite) {
             QUnit.skip(name, wrapTest(testFn))
         } else {
@@ -30,7 +30,7 @@ internal class QUnitAdapter : FrameworkAdapter {
         }
     }
 
-    private fun wrapTest(testFn: () -> Any): (dynamic) -> Any = { assert ->
+    private fun wrapTest(testFn: () -> Any?): (dynamic) -> Any? = { assert ->
         var assertionsHappened = false
         assertHook = { testResult ->
             assertionsHappened = true