diff --git a/libraries/stdlib/api/js-v1/kotlin.kt b/libraries/stdlib/api/js-v1/kotlin.kt
index 8a4c985dea3..dd541d6f8b8 100644
--- a/libraries/stdlib/api/js-v1/kotlin.kt
+++ b/libraries/stdlib/api/js-v1/kotlin.kt
@@ -155,6 +155,8 @@ public inline fun <R> runCatching(block: () -> R): kotlin.Result<R>
 @kotlin.SinceKotlin(version = "1.2")
 public inline fun <R> suspend(noinline block: suspend () -> R): suspend () -> R
 
+@kotlin.DeprecatedSinceKotlin(warningSince = "1.6")
+@kotlin.Deprecated(message = "Synchronization on any object is not supported in Kotlin/JS", replaceWith = kotlin.ReplaceWith(expression = "run(block)", imports = {}))
 @kotlin.internal.InlineOnly
 public inline fun <R> synchronized(lock: kotlin.Any, block: () -> R): R
 
diff --git a/libraries/stdlib/api/js/kotlin.kt b/libraries/stdlib/api/js/kotlin.kt
index 6bacf7ae323..c816fd01792 100644
--- a/libraries/stdlib/api/js/kotlin.kt
+++ b/libraries/stdlib/api/js/kotlin.kt
@@ -118,6 +118,8 @@ public inline fun <R> runCatching(block: () -> R): kotlin.Result<R>
 @kotlin.SinceKotlin(version = "1.2")
 public inline fun <R> suspend(noinline block: suspend () -> R): suspend () -> R
 
+@kotlin.DeprecatedSinceKotlin(warningSince = "1.6")
+@kotlin.Deprecated(message = "Synchronization on any object is not supported in Kotlin/JS", replaceWith = kotlin.ReplaceWith(expression = "run(block)", imports = {}))
 @kotlin.internal.InlineOnly
 public inline fun <R> synchronized(lock: kotlin.Any, block: () -> R): R
 
diff --git a/libraries/stdlib/common/src/kotlin/KotlinH.kt b/libraries/stdlib/common/src/kotlin/KotlinH.kt
index c53615b466a..6a15d527e4c 100644
--- a/libraries/stdlib/common/src/kotlin/KotlinH.kt
+++ b/libraries/stdlib/common/src/kotlin/KotlinH.kt
@@ -58,15 +58,6 @@ public expect fun Float.toRawBits(): Int
 public expect fun Float.Companion.fromBits(bits: Int): Float
 
 
-// From concurrent.kt
-
-@Deprecated("Synchronization on any object is not supported on every platform and will be removed from the common standard library soon.", level = DeprecationLevel.ERROR)
-@Suppress("NO_ACTUAL_FOR_EXPECT")
-public expect inline fun <R> synchronized(lock: Any, block: () -> R): R
-
-
-
-
 // from lazy.kt
 
 public expect fun <T> lazy(initializer: () -> T): Lazy<T>
diff --git a/libraries/stdlib/js/src/kotlin/concurrent.kt b/libraries/stdlib/js/src/kotlin/concurrent.kt
index e50939f02ac..6c265e09579 100644
--- a/libraries/stdlib/js/src/kotlin/concurrent.kt
+++ b/libraries/stdlib/js/src/kotlin/concurrent.kt
@@ -8,8 +8,11 @@ package kotlin
 import kotlin.contracts.*
 
 
+@DeprecatedSinceKotlin(warningSince = "1.6")
+@Deprecated("Synchronization on any object is not supported in Kotlin/JS", ReplaceWith("run(block)"))
 @kotlin.internal.InlineOnly
-public actual inline fun <R> synchronized(lock: Any, block: () -> R): R {
+@Suppress("UNUSED_PARAMETER")
+public inline fun <R> synchronized(lock: Any, block: () -> R): R {
     contract {
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
diff --git a/libraries/stdlib/jvm/src/kotlin/util/Synchronized.kt b/libraries/stdlib/jvm/src/kotlin/util/Synchronized.kt
index bcedeff760f..3dd2d8f343e 100644
--- a/libraries/stdlib/jvm/src/kotlin/util/Synchronized.kt
+++ b/libraries/stdlib/jvm/src/kotlin/util/Synchronized.kt
@@ -14,7 +14,7 @@ import kotlin.jvm.internal.unsafe.*
  * Executes the given function [block] while holding the monitor of the given object [lock].
  */
 @kotlin.internal.InlineOnly
-public actual inline fun <R> synchronized(lock: Any, block: () -> R): R {
+public inline fun <R> synchronized(lock: Any, block: () -> R): R {
     contract {
         callsInPlace(block, InvocationKind.EXACTLY_ONCE)
     }
diff --git a/libraries/stdlib/wasm/src/kotlin/Kotlin.kt b/libraries/stdlib/wasm/src/kotlin/Kotlin.kt
index 80a0335737b..8e810da01de 100644
--- a/libraries/stdlib/wasm/src/kotlin/Kotlin.kt
+++ b/libraries/stdlib/wasm/src/kotlin/Kotlin.kt
@@ -87,9 +87,6 @@ public actual fun Float.Companion.fromBits(bits: Int): Float = wasm_f32_reinterp
 //@Deprecated("Use Volatile annotation from kotlin.jvm package", ReplaceWith("kotlin.jvm.Volatile"), level = DeprecationLevel.WARNING)
 //public typealias Volatile = kotlin.jvm.Volatile
 
-@Deprecated("Synchronization on any object is not supported on every platform and will be removed from the common standard library soon.")
-public actual inline fun <R> synchronized(lock: Any, block: () -> R): R = TODO("Wasm stdlib: Kotlin")
-