diff --git a/reactive/kotlinx-coroutines-reactive/src/Channel.kt b/reactive/kotlinx-coroutines-reactive/src/Channel.kt
index 6cf11b7aa7..df2131b630 100644
--- a/reactive/kotlinx-coroutines-reactive/src/Channel.kt
+++ b/reactive/kotlinx-coroutines-reactive/src/Channel.kt
@@ -20,7 +20,6 @@ import org.reactivestreams.*
  * @param request how many items to request from publisher in advance (optional, one by default).
  */
 @ObsoleteCoroutinesApi
-@Suppress("CONFLICTING_OVERLOADS")
 public fun <T> Publisher<T>.openSubscription(request: Int = 1): ReceiveChannel<T> {
     val channel = SubscriptionChannel<T>(request)
     subscribe(channel)
@@ -28,7 +27,7 @@ public fun <T> Publisher<T>.openSubscription(request: Int = 1): ReceiveChannel<T
 }
 
 // Will be promoted to error in 1.3.0, removed in 1.4.0
-@Deprecated(message = "Use collect instead", level = DeprecationLevel.WARNING, replaceWith = ReplaceWith("this.collect(action)"))
+@Deprecated(message = "Use collect instead", level = DeprecationLevel.ERROR, replaceWith = ReplaceWith("this.collect(action)"))
 public suspend inline fun <T> Publisher<T>.consumeEach(action: (T) -> Unit) =
     openSubscription().consumeEach(action)
 
@@ -36,7 +35,6 @@ public suspend inline fun <T> Publisher<T>.consumeEach(action: (T) -> Unit) =
  * Subscribes to this [Publisher] and performs the specified action for each received element.
  * Cancels subscription if any exception happens during collect.
  */
-@ExperimentalCoroutinesApi // Since 1.2.1, tentatively till 1.3.0
 public suspend inline fun <T> Publisher<T>.collect(action: (T) -> Unit) =
     openSubscription().consumeEach(action)
 
diff --git a/reactive/kotlinx-coroutines-reactive/src/Publish.kt b/reactive/kotlinx-coroutines-reactive/src/Publish.kt
index a7d53876d6..0e3a7b8c11 100644
--- a/reactive/kotlinx-coroutines-reactive/src/Publish.kt
+++ b/reactive/kotlinx-coroutines-reactive/src/Publish.kt
@@ -48,7 +48,7 @@ public fun <T> publish(
 
 @Deprecated(
     message = "CoroutineScope.publish is deprecated in favour of top-level publish",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("publish(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0. Binary compatibility with Spring
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-reactive/src/ReactiveFlow.kt b/reactive/kotlinx-coroutines-reactive/src/ReactiveFlow.kt
index 559068f578..1a3edc842a 100644
--- a/reactive/kotlinx-coroutines-reactive/src/ReactiveFlow.kt
+++ b/reactive/kotlinx-coroutines-reactive/src/ReactiveFlow.kt
@@ -23,14 +23,12 @@ import kotlin.coroutines.*
  * If any of the resulting flow transformations fails, subscription is immediately cancelled and all in-flights elements
  * are discarded.
  */
-@ExperimentalCoroutinesApi
 public fun <T : Any> Publisher<T>.asFlow(): Flow<T> =
     PublisherAsFlow(this, 1)
 
 /**
  * Transforms the given flow to a spec-compliant [Publisher].
  */
-@ExperimentalCoroutinesApi
 public fun <T : Any> Flow<T>.asPublisher(): Publisher<T> = FlowAsPublisher(this)
 
 private class PublisherAsFlow<T : Any>(
diff --git a/reactive/kotlinx-coroutines-reactor/src/Flux.kt b/reactive/kotlinx-coroutines-reactor/src/Flux.kt
index 18b84ac117..389428df11 100644
--- a/reactive/kotlinx-coroutines-reactor/src/Flux.kt
+++ b/reactive/kotlinx-coroutines-reactor/src/Flux.kt
@@ -50,7 +50,7 @@ public fun <T> flux(
 
 @Deprecated(
     message = "CoroutineScope.flux is deprecated in favour of top-level flux",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("flux(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0. Binary compatibility with Spring
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-reactor/src/Mono.kt b/reactive/kotlinx-coroutines-reactor/src/Mono.kt
index b218f6d0c5..76f0418ea6 100644
--- a/reactive/kotlinx-coroutines-reactor/src/Mono.kt
+++ b/reactive/kotlinx-coroutines-reactor/src/Mono.kt
@@ -39,7 +39,7 @@ public fun <T> mono(
 
 @Deprecated(
     message = "CoroutineScope.mono is deprecated in favour of top-level mono",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("mono(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-reactor/src/ReactorFlow.kt b/reactive/kotlinx-coroutines-reactor/src/ReactorFlow.kt
index 6b031ed453..c852c7667f 100644
--- a/reactive/kotlinx-coroutines-reactor/src/ReactorFlow.kt
+++ b/reactive/kotlinx-coroutines-reactor/src/ReactorFlow.kt
@@ -4,7 +4,6 @@
 
 package kotlinx.coroutines.reactor
 
-import kotlinx.coroutines.*
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.flowOn
 import kotlinx.coroutines.reactive.FlowSubscription
@@ -15,7 +14,6 @@ import reactor.core.publisher.Flux
  * Converts the given flow to a cold flux.
  * The original flow is cancelled when the flux subscriber is disposed.
  */
-@ExperimentalCoroutinesApi
 public fun <T: Any> Flow<T>.asFlux(): Flux<T> = FlowAsFlux(this)
 
 private class FlowAsFlux<T : Any>(private val flow: Flow<T>) : Flux<T>() {
diff --git a/reactive/kotlinx-coroutines-reactor/test/FluxMultiTest.kt b/reactive/kotlinx-coroutines-reactor/test/FluxMultiTest.kt
index ae23d3c23d..7203120dae 100644
--- a/reactive/kotlinx-coroutines-reactor/test/FluxMultiTest.kt
+++ b/reactive/kotlinx-coroutines-reactor/test/FluxMultiTest.kt
@@ -73,7 +73,7 @@ class FluxMultiTest : TestBase() {
         val mono = mono {
             var result = ""
             try {
-                flux.consumeEach { result += it }
+                flux.collect { result += it }
             } catch(e: IOException) {
                 result += e.message
             }
diff --git a/reactive/kotlinx-coroutines-rx2/src/RxChannel.kt b/reactive/kotlinx-coroutines-rx2/src/RxChannel.kt
index b038e539fb..dc852b9024 100644
--- a/reactive/kotlinx-coroutines-rx2/src/RxChannel.kt
+++ b/reactive/kotlinx-coroutines-rx2/src/RxChannel.kt
@@ -19,7 +19,6 @@ import kotlinx.coroutines.internal.*
  *           See [issue #254](https://github.com/Kotlin/kotlinx.coroutines/issues/254).
  */
 @ObsoleteCoroutinesApi
-@Suppress("CONFLICTING_OVERLOADS")
 public fun <T> MaybeSource<T>.openSubscription(): ReceiveChannel<T> {
     val channel = SubscriptionChannel<T>()
     subscribe(channel)
@@ -34,7 +33,6 @@ public fun <T> MaybeSource<T>.openSubscription(): ReceiveChannel<T> {
  *           See [issue #254](https://github.com/Kotlin/kotlinx.coroutines/issues/254).
  */
 @ObsoleteCoroutinesApi
-@Suppress("CONFLICTING_OVERLOADS")
 public fun <T> ObservableSource<T>.openSubscription(): ReceiveChannel<T> {
     val channel = SubscriptionChannel<T>()
     subscribe(channel)
@@ -42,12 +40,12 @@ public fun <T> ObservableSource<T>.openSubscription(): ReceiveChannel<T> {
 }
 
 // Will be promoted to error in 1.3.0, removed in 1.4.0
-@Deprecated(message = "Use collect instead", level = DeprecationLevel.WARNING, replaceWith = ReplaceWith("this.collect(action)"))
+@Deprecated(message = "Use collect instead", level = DeprecationLevel.ERROR, replaceWith = ReplaceWith("this.collect(action)"))
 public suspend inline fun <T> MaybeSource<T>.consumeEach(action: (T) -> Unit) =
     openSubscription().consumeEach(action)
 
 // Will be promoted to error in 1.3.0, removed in 1.4.0
-@Deprecated(message = "Use collect instead", level = DeprecationLevel.WARNING, replaceWith = ReplaceWith("this.collect(action)"))
+@Deprecated(message = "Use collect instead", level = DeprecationLevel.ERROR, replaceWith = ReplaceWith("this.collect(action)"))
 public suspend inline fun <T> ObservableSource<T>.consumeEach(action: (T) -> Unit) =
     openSubscription().consumeEach(action)
 
@@ -55,7 +53,6 @@ public suspend inline fun <T> ObservableSource<T>.consumeEach(action: (T) -> Uni
  * Subscribes to this [MaybeSource] and performs the specified action for each received element.
  * Cancels subscription if any exception happens during collect.
  */
-@ExperimentalCoroutinesApi // Since 1.2.1, tentatively till 1.3.0
 public suspend inline fun <T> MaybeSource<T>.collect(action: (T) -> Unit) =
     openSubscription().consumeEach(action)
 
@@ -63,7 +60,6 @@ public suspend inline fun <T> MaybeSource<T>.collect(action: (T) -> Unit) =
  * Subscribes to this [ObservableSource] and performs the specified action for each received element.
  * Cancels subscription if any exception happens during collect.
  */
-@ExperimentalCoroutinesApi // Since 1.2.1, tentatively till 1.3.0
 public suspend inline fun <T> ObservableSource<T>.collect(action: (T) -> Unit) =
     openSubscription().consumeEach(action)
 
diff --git a/reactive/kotlinx-coroutines-rx2/src/RxCompletable.kt b/reactive/kotlinx-coroutines-rx2/src/RxCompletable.kt
index 0da06776a5..c59b4bd6b5 100644
--- a/reactive/kotlinx-coroutines-rx2/src/RxCompletable.kt
+++ b/reactive/kotlinx-coroutines-rx2/src/RxCompletable.kt
@@ -36,7 +36,7 @@ public fun rxCompletable(
 
 @Deprecated(
     message = "CoroutineScope.rxCompletable is deprecated in favour of top-level rxCompletable",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("rxCompletable(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-rx2/src/RxFlowable.kt b/reactive/kotlinx-coroutines-rx2/src/RxFlowable.kt
index beee40eedb..30a1ed7e92 100644
--- a/reactive/kotlinx-coroutines-rx2/src/RxFlowable.kt
+++ b/reactive/kotlinx-coroutines-rx2/src/RxFlowable.kt
@@ -45,7 +45,7 @@ public fun <T: Any> rxFlowable(
 
 @Deprecated(
     message = "CoroutineScope.rxFlowable is deprecated in favour of top-level rxFlowable",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("rxFlowable(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-rx2/src/RxMaybe.kt b/reactive/kotlinx-coroutines-rx2/src/RxMaybe.kt
index fbc366c6df..9f176e938c 100644
--- a/reactive/kotlinx-coroutines-rx2/src/RxMaybe.kt
+++ b/reactive/kotlinx-coroutines-rx2/src/RxMaybe.kt
@@ -37,7 +37,7 @@ public fun <T> rxMaybe(
 
 @Deprecated(
     message = "CoroutineScope.rxMaybe is deprecated in favour of top-level rxMaybe",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("rxMaybe(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-rx2/src/RxObservable.kt b/reactive/kotlinx-coroutines-rx2/src/RxObservable.kt
index 3d0ccd824d..6ccf0f0bae 100644
--- a/reactive/kotlinx-coroutines-rx2/src/RxObservable.kt
+++ b/reactive/kotlinx-coroutines-rx2/src/RxObservable.kt
@@ -46,7 +46,7 @@ public fun <T : Any> rxObservable(
 
 @Deprecated(
     message = "CoroutineScope.rxObservable is deprecated in favour of top-level rxObservable",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("rxObservable(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-rx2/src/RxSingle.kt b/reactive/kotlinx-coroutines-rx2/src/RxSingle.kt
index b6cebf097c..f3573ee6eb 100644
--- a/reactive/kotlinx-coroutines-rx2/src/RxSingle.kt
+++ b/reactive/kotlinx-coroutines-rx2/src/RxSingle.kt
@@ -36,7 +36,7 @@ public fun <T : Any> rxSingle(
 
 @Deprecated(
     message = "CoroutineScope.rxSingle is deprecated in favour of top-level rxSingle",
-    level = DeprecationLevel.WARNING,
+    level = DeprecationLevel.ERROR,
     replaceWith = ReplaceWith("rxSingle(context, block)")
 ) // Since 1.3.0, will be error in 1.3.1 and hidden in 1.4.0
 @LowPriorityInOverloadResolution
diff --git a/reactive/kotlinx-coroutines-rx2/test/CompletableTest.kt b/reactive/kotlinx-coroutines-rx2/test/CompletableTest.kt
index a7caea4793..9a12bafb1d 100644
--- a/reactive/kotlinx-coroutines-rx2/test/CompletableTest.kt
+++ b/reactive/kotlinx-coroutines-rx2/test/CompletableTest.kt
@@ -150,7 +150,7 @@ class CompletableTest : TestBase() {
 
     @Test
     fun testFatalExceptionInSubscribe() = runTest {
-        GlobalScope.rxCompletable(Dispatchers.Unconfined + CoroutineExceptionHandler{ _, e -> assertTrue(e is LinkageError); expect(2)}) {
+        rxCompletable(Dispatchers.Unconfined + CoroutineExceptionHandler{ _, e -> assertTrue(e is LinkageError); expect(2)}) {
             expect(1)
             42
         }.subscribe({ throw LinkageError() })
@@ -159,7 +159,7 @@ class CompletableTest : TestBase() {
 
     @Test
     fun testFatalExceptionInSingle() = runTest {
-        GlobalScope.rxCompletable(Dispatchers.Unconfined) {
+        rxCompletable(Dispatchers.Unconfined) {
             throw LinkageError()
         }.subscribe({ expectUnreached()  }, { expect(1); assertTrue(it is LinkageError) })
         finish(2)
diff --git a/reactive/kotlinx-coroutines-rx2/test/MaybeTest.kt b/reactive/kotlinx-coroutines-rx2/test/MaybeTest.kt
index dcd66638e5..326c83e45c 100644
--- a/reactive/kotlinx-coroutines-rx2/test/MaybeTest.kt
+++ b/reactive/kotlinx-coroutines-rx2/test/MaybeTest.kt
@@ -280,7 +280,7 @@ class MaybeTest : TestBase() {
 
     @Test
     fun testFatalExceptionInSubscribe() = runTest {
-        GlobalScope.rxMaybe(Dispatchers.Unconfined + CoroutineExceptionHandler{ _, e -> assertTrue(e is LinkageError); expect(2)}) {
+        rxMaybe(Dispatchers.Unconfined + CoroutineExceptionHandler{ _, e -> assertTrue(e is LinkageError); expect(2)}) {
             expect(1)
             42
         }.subscribe({ throw LinkageError() })
@@ -289,7 +289,7 @@ class MaybeTest : TestBase() {
 
     @Test
     fun testFatalExceptionInSingle() = runTest {
-        GlobalScope.rxMaybe(Dispatchers.Unconfined) {
+        rxMaybe(Dispatchers.Unconfined) {
             throw LinkageError()
         }.subscribe({ expectUnreached()  }, { expect(1); assertTrue(it is LinkageError) })
         finish(2)
diff --git a/reactive/kotlinx-coroutines-rx2/test/ObservableMultiTest.kt b/reactive/kotlinx-coroutines-rx2/test/ObservableMultiTest.kt
index 75f79de5ca..6971918723 100644
--- a/reactive/kotlinx-coroutines-rx2/test/ObservableMultiTest.kt
+++ b/reactive/kotlinx-coroutines-rx2/test/ObservableMultiTest.kt
@@ -18,7 +18,7 @@ class ObservableMultiTest : TestBase() {
     @Test
     fun testNumbers() {
         val n = 100 * stressTestMultiplier
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             repeat(n) { send(it) }
         }
         checkSingleValue(observable.toList()) { list ->
@@ -30,7 +30,7 @@ class ObservableMultiTest : TestBase() {
     @Test
     fun testConcurrentStress() {
         val n = 10_000 * stressTestMultiplier
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             newCoroutineContext(coroutineContext)
             // concurrent emitters (many coroutines)
             val jobs = List(n) {
@@ -51,7 +51,7 @@ class ObservableMultiTest : TestBase() {
     @Test
     fun testIteratorResendUnconfined() {
         val n = 10_000 * stressTestMultiplier
-        val observable = GlobalScope.rxObservable(Dispatchers.Unconfined) {
+        val observable = rxObservable(Dispatchers.Unconfined) {
             Observable.range(0, n).collect { send(it) }
         }
         checkSingleValue(observable.toList()) { list ->
@@ -62,7 +62,7 @@ class ObservableMultiTest : TestBase() {
     @Test
     fun testIteratorResendPool() {
         val n = 10_000 * stressTestMultiplier
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             Observable.range(0, n).collect { send(it) }
         }
         checkSingleValue(observable.toList()) { list ->
@@ -72,14 +72,14 @@ class ObservableMultiTest : TestBase() {
 
     @Test
     fun testSendAndCrash() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send("O")
             throw IOException("K")
         }
         val single = rxSingle {
             var result = ""
             try {
-                observable.consumeEach { result += it }
+                observable.collect { result += it }
             } catch(e: IOException) {
                 result += e.message
             }
diff --git a/reactive/kotlinx-coroutines-rx2/test/ObservableSingleTest.kt b/reactive/kotlinx-coroutines-rx2/test/ObservableSingleTest.kt
index 6b5d7451a4..2fa1d9b0df 100644
--- a/reactive/kotlinx-coroutines-rx2/test/ObservableSingleTest.kt
+++ b/reactive/kotlinx-coroutines-rx2/test/ObservableSingleTest.kt
@@ -13,7 +13,7 @@ import java.util.concurrent.*
 class ObservableSingleTest {
     @Test
     fun testSingleNoWait() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send("OK")
         }
 
@@ -29,7 +29,7 @@ class ObservableSingleTest {
 
     @Test
     fun testSingleEmitAndAwait() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.just("O").awaitSingle() + "K")
         }
 
@@ -40,7 +40,7 @@ class ObservableSingleTest {
 
     @Test
     fun testSingleWithDelay() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.timer(50, TimeUnit.MILLISECONDS).map { "O" }.awaitSingle() + "K")
         }
 
@@ -51,7 +51,7 @@ class ObservableSingleTest {
 
     @Test
     fun testSingleException() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.just("O", "K").awaitSingle() + "K")
         }
 
@@ -62,7 +62,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirst() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.just("O", "#").awaitFirst() + "K")
         }
 
@@ -73,7 +73,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirstOrDefault() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.empty<String>().awaitFirstOrDefault("O") + "K")
         }
 
@@ -84,7 +84,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirstOrDefaultWithValues() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.just("O", "#").awaitFirstOrDefault("!") + "K")
         }
 
@@ -95,7 +95,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirstOrNull() {
-        val observable = GlobalScope.rxObservable<String> {
+        val observable = rxObservable<String> {
             send(Observable.empty<String>().awaitFirstOrNull() ?: "OK")
         }
 
@@ -106,7 +106,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirstOrNullWithValues() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send((Observable.just("O", "#").awaitFirstOrNull() ?: "!") + "K")
         }
 
@@ -117,7 +117,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirstOrElse() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.empty<String>().awaitFirstOrElse { "O" } + "K")
         }
 
@@ -128,7 +128,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitFirstOrElseWithValues() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.just("O", "#").awaitFirstOrElse { "!" } + "K")
         }
 
@@ -139,7 +139,7 @@ class ObservableSingleTest {
 
     @Test
     fun testAwaitLast() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             send(Observable.just("#", "O").awaitLast() + "K")
         }
 
@@ -150,7 +150,7 @@ class ObservableSingleTest {
 
     @Test
     fun testExceptionFromObservable() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             try {
                 send(Observable.error<String>(RuntimeException("O")).awaitFirst())
             } catch (e: RuntimeException) {
@@ -165,7 +165,7 @@ class ObservableSingleTest {
 
     @Test
     fun testExceptionFromCoroutine() {
-        val observable = GlobalScope.rxObservable<String> {
+        val observable = rxObservable<String> {
             error(Observable.just("O").awaitSingle() + "K")
         }
 
@@ -177,7 +177,7 @@ class ObservableSingleTest {
 
     @Test
     fun testObservableIteration() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             var result = ""
             Observable.just("O", "K").collect { result += it }
             send(result)
@@ -190,7 +190,7 @@ class ObservableSingleTest {
 
     @Test
     fun testObservableIterationFailure() {
-        val observable = GlobalScope.rxObservable {
+        val observable = rxObservable {
             try {
                 Observable.error<String>(RuntimeException("OK")).collect { fail("Should not be here") }
                 send("Fail")
diff --git a/reactive/kotlinx-coroutines-rx2/test/SingleTest.kt b/reactive/kotlinx-coroutines-rx2/test/SingleTest.kt
index fce772347b..9251149375 100644
--- a/reactive/kotlinx-coroutines-rx2/test/SingleTest.kt
+++ b/reactive/kotlinx-coroutines-rx2/test/SingleTest.kt
@@ -201,7 +201,7 @@ class SingleTest : TestBase() {
 
     @Test
     fun testFatalExceptionInSubscribe() = runTest {
-        GlobalScope.rxSingle(Dispatchers.Unconfined + CoroutineExceptionHandler { _, e -> assertTrue(e is LinkageError); expect(2) }) {
+        rxSingle(Dispatchers.Unconfined + CoroutineExceptionHandler { _, e -> assertTrue(e is LinkageError); expect(2) }) {
             expect(1)
             42
         }.subscribe(Consumer {
@@ -212,7 +212,7 @@ class SingleTest : TestBase() {
 
     @Test
     fun testFatalExceptionInSingle() = runTest {
-        GlobalScope.rxSingle(Dispatchers.Unconfined) {
+        rxSingle(Dispatchers.Unconfined) {
             throw LinkageError()
         }.subscribe({ _, e ->  assertTrue(e is LinkageError); expect(1) })