diff --git a/runtime/src/main/kotlin/konan/concurrent.kt b/runtime/src/main/kotlin/konan/concurrent.kt
new file mode 100644
index 00000000000..f5cb1b9ecfc
--- /dev/null
+++ b/runtime/src/main/kotlin/konan/concurrent.kt
@@ -0,0 +1,31 @@
+/*
+ * Copyright 2010-2017 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package kotlin
+
+// Note:
+// Right now we don't want to have neither 'volatile' nor 'synchronized' at runtime.
+
+@Target(AnnotationTarget.PROPERTY, AnnotationTarget.FIELD)
+@Retention(AnnotationRetention.SOURCE)
+public annotation class Volatile
+
+@Target(AnnotationTarget.FUNCTION, AnnotationTarget.PROPERTY_GETTER, AnnotationTarget.PROPERTY_SETTER)
+@Retention(AnnotationRetention.SOURCE)
+public annotation class Synchronized
+
+@kotlin.internal.InlineOnly
+public inline fun <R> synchronized(@Suppress("UNUSED_PARAMETER") lock: Any, crossinline block: () -> R): R = block()
\ No newline at end of file
diff --git a/runtime/src/main/kotlin/kotlin/Annotations.kt b/runtime/src/main/kotlin/kotlin/Annotations.kt
index a7d057fb019..117229298a8 100644
--- a/runtime/src/main/kotlin/kotlin/Annotations.kt
+++ b/runtime/src/main/kotlin/kotlin/Annotations.kt
@@ -108,6 +108,25 @@ public annotation class UnsafeVariance
 @MustBeDocumented
 public annotation class SinceKotlin(val version: String)
 
+/**
+ * When applied to annotation class X specifies that X defines a DSL language
+ *
+ * The general rule:
+ * - an implicit receiver may *belong to a DSL @X* if marked with a corresponding DSL marker annotation
+ * - two implicit receivers of the same DSL are not accessible in the same scope
+ * - the closest one wins
+ * - other available receivers are resolved as usual, but if the resulting resolved call binds to such a receiver, it's a compilation error
+ *
+ * Marking rules: an implicit receiver is considered marked with @Ann if
+ * - its type is marked, or
+ * - its type's classifier is marked
+ * - or any of its superclasses/superinterfaces
+ */
+@Target(ANNOTATION_CLASS)
+@Retention(BINARY)
+@MustBeDocumented
+@SinceKotlin("1.1")
+public annotation class DslMarker
 
 /**
  * Specifies that this part of internal API is effectively public exposed by using in public inline function