diff --git a/libraries/stdlib/test/concurrent/TimerTest.kt b/libraries/stdlib/test/concurrent/TimerTest.kt
index 3e4009f1098..1c79b7d43dc 100644
--- a/libraries/stdlib/test/concurrent/TimerTest.kt
+++ b/libraries/stdlib/test/concurrent/TimerTest.kt
@@ -1,26 +1,32 @@
 @file:kotlin.jvm.JvmVersion
 package test.concurrent
 
+import java.util.*
 import kotlin.concurrent.*
 import kotlin.test.*
 
-import java.util.concurrent.atomic.AtomicInteger
-import java.util.Timer
+import java.util.concurrent.CountDownLatch
+import java.util.concurrent.TimeUnit
+import java.util.concurrent.TimeoutException
 
 
 class TimerTest {
     @Test fun scheduledTask() {
-        val counter = AtomicInteger(0)
         val timer = Timer()
 
-        val task = timer.scheduleAtFixedRate(1000, 100) {
-            val current = counter.incrementAndGet()
-            if (false) println("Timer fired at $current")
+        val latch = CountDownLatch(10)
+        val startedAt = System.nanoTime()
+        lateinit var callbackTask: TimerTask
+        val task = timer.scheduleAtFixedRate(100, 10) {
+            callbackTask = this
+            latch.countDown()
+            if (latch.count == 0L) this.cancel()
         }
-        Thread.sleep(1500)
-        task.cancel()
+        if (!latch.await(1500, TimeUnit.MILLISECONDS)) throw TimeoutException()
+        val elapsed = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startedAt)
 
-        val value = counter.get()
-        assertTrue(value >= 4, "Expected to fire at least 4 times, but was $value")
+        val expectedRange = 100L..500L
+        assertTrue(elapsed in expectedRange, "Expected elapsed ($elapsed ms) to fit in range $expectedRange")
+        assertSame(task, callbackTask)
     }
 }
\ No newline at end of file
diff --git a/libraries/stdlib/test/utils/KotlinVersionTest.kt b/libraries/stdlib/test/utils/KotlinVersionTest.kt
index 39b3ef847bc..71d55f625fe 100644
--- a/libraries/stdlib/test/utils/KotlinVersionTest.kt
+++ b/libraries/stdlib/test/utils/KotlinVersionTest.kt
@@ -60,7 +60,7 @@ class KotlinVersionTest {
         val random = java.util.Random()
         fun randomComponent(): Int = random.nextInt(KotlinVersion.MAX_COMPONENT_VALUE + 1)
         fun randomVersion() = KotlinVersion(randomComponent(), randomComponent(), randomComponent())
-        repeat(10000) {
+        repeat(1000) {
             val v1 = randomVersion()
             val v2 = randomVersion()
             if (v1.isAtLeast(v2.major, v2.minor, v2.patch))
diff --git a/libraries/stdlib/test/utils/LazyJVMTest.kt b/libraries/stdlib/test/utils/LazyJVMTest.kt
index 0c638d9ae26..e6a2668b9cc 100644
--- a/libraries/stdlib/test/utils/LazyJVMTest.kt
+++ b/libraries/stdlib/test/utils/LazyJVMTest.kt
@@ -4,11 +4,13 @@ package test.utils
 
 import kotlin.*
 import kotlin.test.*
-import java.io.*
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.atomic.AtomicInteger
 import kotlin.concurrent.thread
 import test.io.serializeAndDeserialize
+import java.util.*
+import java.util.concurrent.ConcurrentLinkedQueue
+import java.util.concurrent.atomic.AtomicBoolean
 
 class LazyJVMTest {
 
@@ -16,11 +18,12 @@ class LazyJVMTest {
         val counter = AtomicInteger(0)
         val lazy = lazy {
             val value = counter.incrementAndGet()
-            Thread.sleep(100)
+            Thread.sleep(80)
             value
         }
 
-        val accessThreads = listOf(lazy, lazy).map { thread { it.value } }
+        val accessThreads = List(3) { thread(start = false) { lazy.value } }
+        accessThreads.forEach { it.start() }
         accessThreads.forEach { it.join() }
 
         assertEquals(1, counter.get())
@@ -35,7 +38,7 @@ class LazyJVMTest {
         val initializer = {
             val value = counter.incrementAndGet()
             runs += (value to initialized)
-            Thread.sleep(100)
+            Thread.sleep(50)
             initialized = true
             value
         }
@@ -54,26 +57,32 @@ class LazyJVMTest {
 
     @Test fun publishOnceLazy() {
         val counter = AtomicInteger(0)
-        var initialized: Boolean = false
-        val runs = ConcurrentHashMap<Int, Boolean>()
+        val initialized = AtomicBoolean(false)
+        val threads = 3
+        val values = Random().let { r -> List(threads) { 50 + r.nextInt(50) } }
+        data class Run(val id: Int, val value: Int, val initialized: Boolean)
+        val runs = ConcurrentLinkedQueue<Run>()
 
         val initializer = {
-            val value = counter.incrementAndGet()
-            runs += (value to initialized)
-            Thread.sleep((3 - value) * 100L)
-            initialized = true
+            val id = counter.getAndIncrement()
+            val value = values[id]
+            runs += Run(id, value, initialized.get())
+            Thread.sleep(value.toLong())
+            initialized.set(true)
             value
         }
         val lazy = lazy(LazyThreadSafetyMode.PUBLICATION, initializer)
 
-        val accessThreads = listOf(lazy, lazy).map { thread { it.value } }
+        val accessThreads = List(threads) { thread(start = false) { lazy.value } }
+        accessThreads.forEach { it.start() }
+        val result = run { while (!lazy.isInitialized()) /* wait */; lazy.value }
         accessThreads.forEach { it.join() }
 
-        assertEquals(2, counter.get())
-        assertEquals(2, lazy.value)
-        @Suppress("NAME_SHADOWING")
-        for ((_, initialized) in runs) {
-            assertFalse(initialized, "Expected uninitialized on first and second run")
+        assertEquals(threads, counter.get())
+        assertEquals(result, lazy.value, "Value must not change after isInitialized is set: $lazy, runs: $runs")
+
+        runs.forEach {
+            assertFalse(it.initialized, "Expected uninitialized on all initializer executions, runs: $runs")
         }
     }