diff --git a/build.gradle.kts b/build.gradle.kts
index d1667d7b9..4d15bfe0d 100644
--- a/build.gradle.kts
+++ b/build.gradle.kts
@@ -4,6 +4,7 @@ buildscript {
     val kotlinVersion: String by rootProject.extra("1.3.20")
     val ioVersion: String by rootProject.extra("0.1.2")
     val coroutinesVersion: String by rootProject.extra("1.1.1")
+    val atomicfuVersion: String by rootProject.extra("0.12.1")
 
     repositories {
         //maven("https://dl.bintray.com/kotlin/kotlin-eap")
diff --git a/kmath-coroutines/build.gradle b/kmath-coroutines/build.gradle
index 7149e8bb9..2c58a4112 100644
--- a/kmath-coroutines/build.gradle
+++ b/kmath-coroutines/build.gradle
@@ -3,13 +3,8 @@ plugins {
 }
 
 kotlin {
-    targets {
-        fromPreset(presets.jvm, 'jvm')
-        // For ARM, preset should be changed to presets.iosArm32 or presets.iosArm64
-        // For Linux, preset should be changed to e.g. presets.linuxX64
-        // For MacOS, preset should be changed to e.g. presets.macosX64
-        //fromPreset(presets.mingwX64, 'mingw')
-    }
+    jvm()
+    js()
     sourceSets {
         commonMain {
             dependencies {
@@ -34,6 +29,11 @@ kotlin {
                 implementation 'org.jetbrains.kotlin:kotlin-test-junit'
             }
         }
+        jsMain{
+            dependencies{
+                api "org.jetbrains.kotlinx:kotlinx-coroutines-core-js:$coroutinesVersion"
+            }
+        }
 //        mingwMain {
 //        }
 //        mingwTest {
diff --git a/kmath-coroutines/src/jsMain/kotlin/scientifik/kmath/structures/runBlocking.kt b/kmath-coroutines/src/jsMain/kotlin/scientifik/kmath/structures/runBlocking.kt
new file mode 100644
index 000000000..7331d1801
--- /dev/null
+++ b/kmath-coroutines/src/jsMain/kotlin/scientifik/kmath/structures/runBlocking.kt
@@ -0,0 +1,11 @@
+package scientifik.kmath.structures
+
+import kotlinx.coroutines.CoroutineScope
+import kotlin.coroutines.CoroutineContext
+
+actual fun <R> runBlocking(
+    context: CoroutineContext,
+    function: suspend CoroutineScope.() -> R
+): R {
+    TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
+}
\ No newline at end of file
diff --git a/kmath-coroutines/src/jvmMain/kotlin/scientifik/kmath/structures/_CoroutinesExtra.kt b/kmath-coroutines/src/jvmMain/kotlin/scientifik/kmath/structures/runBlocking.kt
similarity index 100%
rename from kmath-coroutines/src/jvmMain/kotlin/scientifik/kmath/structures/_CoroutinesExtra.kt
rename to kmath-coroutines/src/jvmMain/kotlin/scientifik/kmath/structures/runBlocking.kt
diff --git a/kmath-sequential/build.gradle.kts b/kmath-sequential/build.gradle.kts
index 57467d7b8..391504f23 100644
--- a/kmath-sequential/build.gradle.kts
+++ b/kmath-sequential/build.gradle.kts
@@ -1,19 +1,20 @@
 plugins {
     kotlin("multiplatform")
-    id("kotlinx-atomicfu")
+    id("kotlinx-atomicfu") version "0.12.1"
 }
 
+val atomicfuVersion: String by rootProject.extra
 
 kotlin {
     jvm ()
-    js()
+    //js()
 
     sourceSets {
         val commonMain by getting {
             dependencies {
                 api(project(":kmath-core"))
                 api(project(":kmath-coroutines"))
-                compileOnly("org.jetbrains.kotlinx:atomicfu-common:0.12.1")
+                compileOnly("org.jetbrains.kotlinx:atomicfu-common:$atomicfuVersion")
             }
         }
         val commonTest by getting {
@@ -24,7 +25,7 @@ kotlin {
         }
         val jvmMain by getting {
             dependencies {
-                compileOnly("org.jetbrains.kotlinx:atomicfu:0.12.1")
+                compileOnly("org.jetbrains.kotlinx:atomicfu:$atomicfuVersion")
             }
         }
         val jvmTest by getting {
@@ -35,17 +36,18 @@ kotlin {
         }
 //        val jsMain by getting {
 //            dependencies {
-//                api(kotlin("stdlib-js"))
+//                compileOnly("org.jetbrains.kotlinx:atomicfu-js:$atomicfuVersion")
 //            }
 //        }
-        val jsTest by getting {
-            dependencies {
-                implementation(kotlin("test-js"))
-            }
-        }
-//        mingwMain {
-//        }
-//        mingwTest {
+//        val jsTest by getting {
+//            dependencies {
+//                implementation(kotlin("test-js"))
+//            }
 //        }
+
     }
+}
+
+atomicfu {
+    variant = "VH"
 }
\ No newline at end of file
diff --git a/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Accumulators.kt b/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Accumulators.kt
index 94ac0ac2e..ef7950519 100644
--- a/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Accumulators.kt
+++ b/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Accumulators.kt
@@ -1,10 +1,7 @@
 package scientifik.kmath.sequential
 
 import kotlinx.atomicfu.atomic
-import kotlinx.atomicfu.atomicArrayOfNulls
 import kotlinx.atomicfu.getAndUpdate
-import kotlinx.coroutines.GlobalScope
-import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.ReceiveChannel
 import scientifik.kmath.operations.Space
 
@@ -46,7 +43,7 @@ suspend fun <T> Accumulator<T>.offerAll(channel: ReceiveChannel<T>) {
  */
 class GenericMean<T : Any>(val context: Space<T>) : Accumulator<T> {
     //TODO add guard against overflow
-    val counter = atomic(0)
+    private val counter = atomic(0)
     val sum = atomic(context.zero)
 
     val value get() = with(context) { sum.value / counter.value }
diff --git a/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Chain.kt b/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Chain.kt
index abecf014d..7633b2223 100644
--- a/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Chain.kt
+++ b/kmath-sequential/src/commonMain/kotlin/scientifik/kmath/sequential/Chain.kt
@@ -97,11 +97,12 @@ class MarkovChain<out R : Any>(private val seed: () -> R, private val gen: suspe
 
     constructor(seed: R, gen: suspend (R) -> R) : this({ seed }, gen)
 
-    private val atomicValue by lazy { atomic(seed()) }
-    override val value: R get() = atomicValue.value
+    private val atomicValue = atomic<R?>(null)
+    override val value: R get() = atomicValue.value ?: seed()
 
     override suspend fun next(): R {
-        atomicValue.lazySet(gen(value))
+        val newValue = gen(value)
+        atomicValue.lazySet(newValue)
         return value
     }
 
@@ -122,11 +123,12 @@ class StatefulChain<S, out R>(
 
     constructor(state: S, seed: R, gen: suspend S.(R) -> R) : this(state, { seed }, gen)
 
-    private val atomicValue by lazy { atomic(seed(state)) }
-    override val value: R get() = atomicValue.value
+    private val atomicValue = atomic<R?>(null)
+    override val value: R get() = atomicValue.value ?: seed(state)
 
     override suspend fun next(): R {
-        atomicValue.lazySet(gen(state, value))
+        val newValue = gen(state, value)
+        atomicValue.lazySet(newValue)
         return value
     }
 
diff --git a/kmath-core/src/commonTest/kotlin/scientifik/kmath/misc/CumulativeKtTest.kt b/kmath-sequential/src/commonTest/scientifik/kmath/sequential/CumulativeKtTest.kt
similarity index 100%
rename from kmath-core/src/commonTest/kotlin/scientifik/kmath/misc/CumulativeKtTest.kt
rename to kmath-sequential/src/commonTest/scientifik/kmath/sequential/CumulativeKtTest.kt
diff --git a/kmath-sequential/src/jvmMain/kotlin/scientifik/kmath/sequential/AccumulatorsExt.kt b/kmath-sequential/src/jvmMain/kotlin/scientifik/kmath/sequential/AccumulatorsExt.kt
index cc9a07668..37190f8f3 100644
--- a/kmath-sequential/src/jvmMain/kotlin/scientifik/kmath/sequential/AccumulatorsExt.kt
+++ b/kmath-sequential/src/jvmMain/kotlin/scientifik/kmath/sequential/AccumulatorsExt.kt
@@ -2,6 +2,8 @@ package scientifik.kmath.sequential
 
 import kotlinx.coroutines.channels.Channel
 import kotlinx.coroutines.channels.ReceiveChannel
+import kotlinx.coroutines.sync.Mutex
+import kotlinx.coroutines.sync.withLock
 import scientifik.kmath.operations.Space
 import scientifik.kmath.structures.runBlocking
 import java.util.*
@@ -12,13 +14,16 @@ import java.util.*
 class MovingAverage<T : Any>(val window: Int, val context: Space<T>) : Accumulator<T> {
     private val outputChannel = Channel<T>()
     private val queue = ArrayDeque<T>(window)
+    private val mutex = Mutex()
 
     override suspend fun send(value: T) {
-        queue.add(value)
-        if (queue.size == window) {
-            val sum = queue.fold(context.zero) { a, b -> context.run { a + b } }
-            outputChannel.send(context.run { sum / window })
-            queue.pop()
+        mutex.withLock {
+            queue.add(value)
+            if (queue.size == window) {
+                val sum = queue.fold(context.zero) { a, b -> context.run { a + b } }
+                outputChannel.send(context.run { sum / window })
+                queue.pop()
+            }
         }
     }
 
diff --git a/settings.gradle.kts b/settings.gradle.kts
index 5638223fc..7045009ca 100644
--- a/settings.gradle.kts
+++ b/settings.gradle.kts
@@ -1,13 +1,3 @@
-buildscript {
-    dependencies {
-        classpath("org.jetbrains.kotlinx:atomicfu-gradle-plugin:0.12.1")
-    }
-
-    repositories {
-        jcenter()
-    }
-}
-
 pluginManagement {
     repositories {
         mavenCentral()
@@ -18,7 +8,7 @@ pluginManagement {
         eachPlugin {
             when (requested.id.id) {
                 "kotlinx-atomicfu" -> {
-                    useModule("org.jetbrains.kotlinx:atomicfu-gradle-plugin:0.12.1")
+                    useModule("org.jetbrains.kotlinx:atomicfu-gradle-plugin:${requested.version}")
                 }
             }
         }