diff --git a/Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Generated.kt b/Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Generated.kt
index 1ecf951711c..323811d4e53 100644
--- a/Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Generated.kt
+++ b/Interop/Runtime/src/main/kotlin/kotlinx/cinterop/Generated.kt
@@ -134,16 +134,13 @@ inline operator fun <T : UByteVarOf<*>> CPointer<T>?.plus(index: Int): CPointer<
 inline operator fun <T : UByte> CPointer<UByteVarOf<T>>.get(index: Int): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$UByte")
 inline operator fun <T : UByte> CPointer<UByteVarOf<T>>.set(index: Int, value: T) {
     (this + index)!!.pointed.value = value
 }
 
-@JvmName("get\$UByte")
 inline operator fun <T : UByte> CPointer<UByteVarOf<T>>.get(index: Long): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$UByte")
 inline operator fun <T : UByte> CPointer<UByteVarOf<T>>.set(index: Long, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -160,7 +157,6 @@ inline operator fun <T : UShortVarOf<*>> CPointer<T>?.plus(index: Int): CPointer
 inline operator fun <T : UShort> CPointer<UShortVarOf<T>>.get(index: Int): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$UShort")
 inline operator fun <T : UShort> CPointer<UShortVarOf<T>>.set(index: Int, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -169,7 +165,6 @@ inline operator fun <T : UShort> CPointer<UShortVarOf<T>>.set(index: Int, value:
 inline operator fun <T : UShort> CPointer<UShortVarOf<T>>.get(index: Long): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$UShort")
 inline operator fun <T : UShort> CPointer<UShortVarOf<T>>.set(index: Long, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -186,7 +181,6 @@ inline operator fun <T : UIntVarOf<*>> CPointer<T>?.plus(index: Int): CPointer<T
 inline operator fun <T : UInt> CPointer<UIntVarOf<T>>.get(index: Int): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$UInt")
 inline operator fun <T : UInt> CPointer<UIntVarOf<T>>.set(index: Int, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -195,7 +189,6 @@ inline operator fun <T : UInt> CPointer<UIntVarOf<T>>.set(index: Int, value: T)
 inline operator fun <T : UInt> CPointer<UIntVarOf<T>>.get(index: Long): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$UInt")
 inline operator fun <T : UInt> CPointer<UIntVarOf<T>>.set(index: Long, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -212,7 +205,6 @@ inline operator fun <T : ULongVarOf<*>> CPointer<T>?.plus(index: Int): CPointer<
 inline operator fun <T : ULong> CPointer<ULongVarOf<T>>.get(index: Int): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$ULong")
 inline operator fun <T : ULong> CPointer<ULongVarOf<T>>.set(index: Int, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -221,7 +213,6 @@ inline operator fun <T : ULong> CPointer<ULongVarOf<T>>.set(index: Int, value: T
 inline operator fun <T : ULong> CPointer<ULongVarOf<T>>.get(index: Long): T =
         (this + index)!!.pointed.value
 
-@JvmName("set\$ULong")
 inline operator fun <T : ULong> CPointer<ULongVarOf<T>>.set(index: Long, value: T) {
     (this + index)!!.pointed.value = value
 }
@@ -322,4 +313,4 @@ gen ULong 8
 gen Float 4
 gen Double 8
 
- */
\ No newline at end of file
+ */
diff --git a/backend.native/build.gradle b/backend.native/build.gradle
index 3785c528d23..7a38e97fbfb 100644
--- a/backend.native/build.gradle
+++ b/backend.native/build.gradle
@@ -183,6 +183,7 @@ targetList.each { target ->
                 '-Xmulti-platform', '-Xuse-experimental=kotlin.Experimental',
                 '-Xuse-experimental=kotlin.contracts.ExperimentalContracts',
                 '-Xuse-experimental=kotlin.ExperimentalMultiplatform',
+                '-Xallow-result-return-type',
                 commonSrc.absolutePath,
                 project(':Interop:Runtime').file('src/main/kotlin'),
                 project(':Interop:Runtime').file('src/native/kotlin'),
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/irasdescriptors/FakeIrUtils.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/irasdescriptors/FakeIrUtils.kt
index 4ad7bbee636..4f5602ab050 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/irasdescriptors/FakeIrUtils.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/irasdescriptors/FakeIrUtils.kt
@@ -7,7 +7,6 @@ package org.jetbrains.kotlin.backend.konan.irasdescriptors
 
 import org.jetbrains.kotlin.backend.konan.*
 import org.jetbrains.kotlin.backend.konan.llvm.llvmSymbolOrigin
-import org.jetbrains.kotlin.idea.MainFunctionDetector
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.toKotlinType
@@ -38,7 +37,5 @@ internal fun IrFunction.isExternalObjCClassMethod() = this.descriptor.isExternal
 
 internal val IrDeclaration.llvmSymbolOrigin get() = this.descriptor.llvmSymbolOrigin
 
-internal fun IrFunction.isMain() = MainFunctionDetector.isMain(this.descriptor)
-
 internal fun IrType.isObjCObjectType() = this.toKotlinType().isObjCObjectType()
 
diff --git a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt
index 385b96b4fa8..12763332655 100644
--- a/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt
+++ b/backend.native/compiler/ir/backend.native/src/org/jetbrains/kotlin/backend/konan/llvm/LlvmDeclarations.kt
@@ -407,7 +407,7 @@ private class DeclarationsGeneratorVisitor(override val context: Context) :
         } else {
             val symbolName = if (descriptor.isExported()) {
                 descriptor.symbolName.also {
-                    if (!descriptor.isMain()) {
+                    if (descriptor.name.asString() != "main") {
                         assert(LLVMGetNamedFunction(context.llvm.llvmModule, it) == null) { it }
                     } else {
                         // As a workaround, allow `main` functions to clash because frontend accepts this.
diff --git a/backend.native/tests/build.gradle b/backend.native/tests/build.gradle
index 7c8059b0c91..3ced68dd29e 100644
--- a/backend.native/tests/build.gradle
+++ b/backend.native/tests/build.gradle
@@ -43,7 +43,7 @@ repositories {
 
 dependencies {
     cli_bc project(path: ':backend.native', configuration: 'cli_bc')
-    update_tests (group: 'org',  name: 'Kotlin_dev_CompilerAllPlugins', version: testKotlinVersion) {
+    update_tests (group: 'org',  name: 'Kotlin_130_Compiler', version: testKotlinVersion) {
         artifact {
             name = 'internal/kotlin-test-data'
             type = 'zip'
diff --git a/gradle.properties b/gradle.properties
index 83d10b85219..453d09d17ba 100644
--- a/gradle.properties
+++ b/gradle.properties
@@ -15,13 +15,13 @@
 #
 
 # A version of the Kotlin "toolchain" (compiler, runtime, stdlib etc) used by the build script.
-buildKotlinVersion=1.3-M2
-buildKotlinCompilerRepo=http://dl.bintray.com/kotlin/kotlin-eap
+buildKotlinVersion=1.3.0-rc-6
+buildKotlinCompilerRepo=http://dl.bintray.com/kotlin/kotlin-dev
 remoteRoot=konan_tests
 testDataVersion=1226829:id
-kotlinCompilerRepo=https://teamcity.jetbrains.com/guestAuth/app/rest/builds/buildType:(id:Kotlin_dev_CompilerAllPlugins),number:1.3.0-dev-391,tag:kotlin-native,pinned:true,branch:(default:any)/artifacts/content/maven
-kotlinVersion=1.3.0-dev-391
-testKotlinVersion=1.3.0-dev-391
+kotlinCompilerRepo=https://teamcity.jetbrains.com/guestAuth/app/rest/builds/buildType:(id:Kotlin_130_Compiler),number:1.3.0-rc-6,branch:(default:any)/artifacts/content/maven
+kotlinVersion=1.3.0-rc-6
+testKotlinVersion=1.3.0-rc-6
 konanVersion=0.9
 org.gradle.jvmargs='-Dfile.encoding=UTF-8'
 org.gradle.workers.max=4
diff --git a/runtime/src/main/kotlin/kotlin/Exceptions.kt b/runtime/src/main/kotlin/kotlin/Exceptions.kt
index de98b81ea06..84b2a6d555f 100644
--- a/runtime/src/main/kotlin/kotlin/Exceptions.kt
+++ b/runtime/src/main/kotlin/kotlin/Exceptions.kt
@@ -171,4 +171,14 @@ public open class IllegalCharacterConversionException : IllegalArgumentException
     constructor(): super()
 
     constructor(message: String?) : super(message)
+}
+
+public actual open class ConcurrentModificationException actual constructor(message: String?, cause: Throwable?) :
+        RuntimeException(message, cause) {
+
+    actual constructor() : this(null, null)
+
+    actual constructor(message: String?) : this(message, null)
+
+    actual constructor(cause: Throwable?) : this(null, cause)
 }
\ No newline at end of file
diff --git a/runtime/src/main/kotlin/kotlin/coroutines/intrinsics/IntrinsicsNative.kt b/runtime/src/main/kotlin/kotlin/coroutines/intrinsics/IntrinsicsNative.kt
index 0198f920dba..8baefee5fe2 100644
--- a/runtime/src/main/kotlin/kotlin/coroutines/intrinsics/IntrinsicsNative.kt
+++ b/runtime/src/main/kotlin/kotlin/coroutines/intrinsics/IntrinsicsNative.kt
@@ -180,12 +180,4 @@ private inline fun <T> createCoroutineFromSuspendFunction(
                         else -> error("This coroutine had already completed")
                     }
         }
-}
-
-/**
- * This value is used as a return value of [suspendCoroutineOrReturn] `block` argument to state that
- * the execution was suspended and will not return any result immediately.
- */
-@SinceKotlin("1.3")
-public actual val COROUTINE_SUSPENDED: Any
-    get() = CoroutineSingletons.COROUTINE_SUSPENDED
\ No newline at end of file
+}
\ No newline at end of file
diff --git a/runtime/src/main/kotlin/kotlin/reflect/KCallable.kt b/runtime/src/main/kotlin/kotlin/reflect/KCallable.kt
index 4c74203d1a7..a3ca665e6d4 100644
--- a/runtime/src/main/kotlin/kotlin/reflect/KCallable.kt
+++ b/runtime/src/main/kotlin/kotlin/reflect/KCallable.kt
@@ -12,8 +12,7 @@ import kotlin.native.internal.FixmeReflection
  *
  * @param R return type of the callable.
  */
-@FixmeReflection
-public interface KCallable<out R> : KAnnotatedElement {
+public actual interface KCallable<out R> : KAnnotatedElement {
     /**
      * The name of this callable as it was declared in the source code.
      * If the callable has no name, a special invented name is created.
@@ -22,7 +21,7 @@ public interface KCallable<out R> : KAnnotatedElement {
      * - property accessors: the getter for a property named "foo" will have the name "<get-foo>",
      *   the setter, similarly, will have the name "<set-foo>".
      */
-    public val name: String
+    public actual val name: String
 
     /**
      * The type of values returned by this callable.
diff --git a/runtime/src/main/kotlin/kotlin/reflect/KClass.kt b/runtime/src/main/kotlin/kotlin/reflect/KClass.kt
index f88c3cbb81a..c7d6a5b7979 100644
--- a/runtime/src/main/kotlin/kotlin/reflect/KClass.kt
+++ b/runtime/src/main/kotlin/kotlin/reflect/KClass.kt
@@ -13,12 +13,12 @@ package kotlin.reflect
  *
  * @param T the type of the class.
  */
-public interface KClass<T : Any> : KDeclarationContainer, KAnnotatedElement, KClassifier {
+public actual interface KClass<T : Any> : KDeclarationContainer, KAnnotatedElement, KClassifier {
     /**
      * The simple name of the class as it was declared in the source code,
      * or `null` if the class has no name (if, for example, it is an anonymous object literal).
      */
-    public val simpleName: String?
+    public actual val simpleName: String?
 
     /**
      * The fully qualified dot-separated name of the class,
diff --git a/runtime/src/main/kotlin/kotlin/reflect/KProperty.kt b/runtime/src/main/kotlin/kotlin/reflect/KProperty.kt
index 42fbdfba0be..8d013c6a0c3 100644
--- a/runtime/src/main/kotlin/kotlin/reflect/KProperty.kt
+++ b/runtime/src/main/kotlin/kotlin/reflect/KProperty.kt
@@ -15,48 +15,40 @@ import kotlin.native.internal.FixmeReflection
  *
  * @param R the type of the property.
  */
-@FixmeReflection
-public interface KProperty<out R> : KCallable<R>
+public actual interface KProperty<out R> : KCallable<R>
 
-@FixmeReflection
-public interface KProperty0<out R> : kotlin.reflect.KProperty<R>, () -> R {
+public actual interface KProperty0<out R> : kotlin.reflect.KProperty<R>, () -> R {
 
-    public abstract fun get(): R
+    public actual fun get(): R
 
     public override abstract operator fun invoke(): R
 }
 
-@FixmeReflection
-public interface KProperty1<T, out R> : kotlin.reflect.KProperty<R>, (T) -> R {
-    public abstract fun get(p1: T): R
+public actual interface KProperty1<T, out R> : kotlin.reflect.KProperty<R>, (T) -> R {
+    public actual fun get(receiver: T): R
 
-    public override abstract operator fun invoke(p1: T): R
+    public override operator fun invoke(p1: T): R
 }
 
-@FixmeReflection
-public interface KProperty2<T1, T2, out R> : kotlin.reflect.KProperty<R>, (T1, T2) -> R {
-    public abstract fun get(p1: T1, p2: T2): R
+public actual interface KProperty2<T1, T2, out R> : kotlin.reflect.KProperty<R>, (T1, T2) -> R {
+    public actual fun get(receiver1: T1, receiver2: T2): R
 
-    public override abstract operator fun invoke(p1: T1, p2: T2): R
+    public override operator fun invoke(p1: T1, p2: T2): R
 }
 
 /**
  * Represents a property declared as a `var`.
  */
-@FixmeReflection
-public interface KMutableProperty<R> : KProperty<R>
+public actual interface KMutableProperty<R> : KProperty<R>
 
-@FixmeReflection
-public interface KMutableProperty0<R> : KProperty0<R>, KMutableProperty<R> {
-    public abstract fun set(value: R)
+public actual interface KMutableProperty0<R> : KProperty0<R>, KMutableProperty<R> {
+    public actual fun set(value: R)
 }
 
-@FixmeReflection
-public interface KMutableProperty1<T, R> : KProperty1<T, R>, KMutableProperty<R> {
-    public abstract fun set(receiver: T, value: R)
+public actual interface KMutableProperty1<T, R> : KProperty1<T, R>, KMutableProperty<R> {
+    public actual fun set(receiver: T, value: R)
 }
 
-@FixmeReflection
-public interface KMutableProperty2<T1, T2, R> : KProperty2<T1, T2, R>, KMutableProperty<R> {
-    public abstract fun set(receiver1: T1, receiver2: T2, value: R)
+public actual interface KMutableProperty2<T1, T2, R> : KProperty2<T1, T2, R>, KMutableProperty<R> {
+    public actual fun set(receiver1: T1, receiver2: T2, value: R)
 }
\ No newline at end of file
diff --git a/samples/calculator/android/build.gradle b/samples/calculator/android/build.gradle
index 0e2b6dd6944..3c9cf238013 100644
--- a/samples/calculator/android/build.gradle
+++ b/samples/calculator/android/build.gradle
@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.3-M2'
+    ext.kotlin_version = '1.3.0-rc-6'
 
     repositories {
         google()
diff --git a/samples/calculator/build.gradle b/samples/calculator/build.gradle
index 71d73abb85b..bfefa0e3edf 100644
--- a/samples/calculator/build.gradle
+++ b/samples/calculator/build.gradle
@@ -1,12 +1,12 @@
 allprojects {
     buildscript {
         repositories {
-            maven { url "http://dl.bintray.com/kotlin/kotlin-eap" }
+            maven { url "http://dl.bintray.com/kotlin/kotlin-dev" }
         }
     }
 
     repositories {
-        maven { url "http://dl.bintray.com/kotlin/kotlin-eap" }
+        maven { url "http://dl.bintray.com/kotlin/kotlin-dev" }
     }
 }
 
@@ -20,4 +20,4 @@ task clean {
     subprojects.each {
         dependsOn("${it.path}:clean")
     }
-}
\ No newline at end of file
+}
diff --git a/samples/calculator/common/build.gradle b/samples/calculator/common/build.gradle
index 241d8d4e898..81b0de4d771 100644
--- a/samples/calculator/common/build.gradle
+++ b/samples/calculator/common/build.gradle
@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.3-M2'
+    ext.kotlin_version = '1.3.0-rc-6'
 
     repositories {
         mavenCentral()
diff --git a/samples/calculator/jvm/build.gradle b/samples/calculator/jvm/build.gradle
index ca9f3f91643..4ea69932403 100644
--- a/samples/calculator/jvm/build.gradle
+++ b/samples/calculator/jvm/build.gradle
@@ -1,5 +1,5 @@
 buildscript {
-    ext.kotlin_version = '1.3-M2'
+    ext.kotlin_version = '1.3.0-rc-6'
 
     repositories {
         mavenCentral()
diff --git a/tools/kotlin-native-gradle-plugin/build.gradle b/tools/kotlin-native-gradle-plugin/build.gradle
index d52e5fd9a84..c0998571ef4 100644
--- a/tools/kotlin-native-gradle-plugin/build.gradle
+++ b/tools/kotlin-native-gradle-plugin/build.gradle
@@ -79,8 +79,8 @@ dependencies {
     bundleDependencies "org.jetbrains.kotlin:kotlin-native-shared:$konanVersion"
 
     testImplementation 'junit:junit:4.12'
-    testImplementation "org.jetbrains.kotlin:kotlin-test:1.3-M2"
-    testImplementation "org.jetbrains.kotlin:kotlin-test-junit:1.3-M2"
+    testImplementation "org.jetbrains.kotlin:kotlin-test:1.3.0-rc-6"
+    testImplementation "org.jetbrains.kotlin:kotlin-test-junit:1.3.0-rc-6"
     testImplementation "org.tools4j:tools4j-spockito:1.6"
     testImplementation('org.spockframework:spock-core:1.1-groovy-2.4') {
         exclude module: 'groovy-all'