diff --git a/compiler/testData/builtin-classes.txt b/compiler/testData/builtin-classes.txt
index 145264f54be..4ae5001b6fc 100644
--- a/compiler/testData/builtin-classes.txt
+++ b/compiler/testData/builtin-classes.txt
@@ -274,8 +274,8 @@ public interface Cloneable {
 public interface Collection</*0*/ out E> : kotlin.Iterable<E> {
     public abstract val size: kotlin.Int
         public abstract fun <get-size>(): kotlin.Int
-    public abstract operator fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
-    public abstract fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
+    public abstract operator fun contains(/*0*/ o: @kotlin.UnsafeVariance() E): kotlin.Boolean
+    public abstract fun containsAll(/*0*/ c: kotlin.Collection<@kotlin.UnsafeVariance() E>): kotlin.Boolean
     public abstract fun isEmpty(): kotlin.Boolean
     public abstract override /*1*/ fun iterator(): kotlin.Iterator<E>
 }
@@ -771,8 +771,8 @@ public interface Iterator</*0*/ out T> {
 public interface List</*0*/ out E> : kotlin.Collection<E> {
     public abstract override /*1*/ val size: kotlin.Int
         public abstract override /*1*/ fun <get-size>(): kotlin.Int
-    public abstract override /*1*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
-    public abstract override /*1*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
+    public abstract override /*1*/ fun contains(/*0*/ o: @kotlin.UnsafeVariance() E): kotlin.Boolean
+    public abstract override /*1*/ fun containsAll(/*0*/ c: kotlin.Collection<@kotlin.UnsafeVariance() E>): kotlin.Boolean
     public abstract operator fun get(/*0*/ index: kotlin.Int): E
     public abstract fun indexOf(/*0*/ o: kotlin.Any?): kotlin.Int
     public abstract override /*1*/ fun isEmpty(): kotlin.Boolean
@@ -951,8 +951,8 @@ public interface MutableCollection</*0*/ E> : kotlin.Collection<E>, kotlin.Mutab
     public abstract fun add(/*0*/ e: E): kotlin.Boolean
     public abstract fun addAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract fun clear(): kotlin.Unit
-    public abstract override /*1*/ /*fake_override*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
-    public abstract override /*1*/ /*fake_override*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
+    public abstract override /*1*/ /*fake_override*/ fun contains(/*0*/ o: E): kotlin.Boolean
+    public abstract override /*1*/ /*fake_override*/ fun containsAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract override /*1*/ /*fake_override*/ fun isEmpty(): kotlin.Boolean
     public abstract override /*2*/ fun iterator(): kotlin.MutableIterator<E>
     public abstract fun remove(/*0*/ o: kotlin.Any?): kotlin.Boolean
@@ -978,8 +978,8 @@ public interface MutableList</*0*/ E> : kotlin.List<E>, kotlin.MutableCollection
     public abstract override /*1*/ fun addAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract fun addAll(/*0*/ index: kotlin.Int, /*1*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract override /*1*/ fun clear(): kotlin.Unit
-    public abstract override /*2*/ /*fake_override*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
-    public abstract override /*2*/ /*fake_override*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun contains(/*0*/ o: E): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun containsAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract override /*1*/ /*fake_override*/ fun get(/*0*/ index: kotlin.Int): E
     public abstract override /*1*/ /*fake_override*/ fun indexOf(/*0*/ o: kotlin.Any?): kotlin.Int
     public abstract override /*2*/ /*fake_override*/ fun isEmpty(): kotlin.Boolean
@@ -1035,8 +1035,8 @@ public interface MutableSet</*0*/ E> : kotlin.Set<E>, kotlin.MutableCollection<E
     public abstract override /*1*/ fun add(/*0*/ e: E): kotlin.Boolean
     public abstract override /*1*/ fun addAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract override /*1*/ fun clear(): kotlin.Unit
-    public abstract override /*2*/ /*fake_override*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
-    public abstract override /*2*/ /*fake_override*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun contains(/*0*/ o: E): kotlin.Boolean
+    public abstract override /*2*/ /*fake_override*/ fun containsAll(/*0*/ c: kotlin.Collection<E>): kotlin.Boolean
     public abstract override /*2*/ /*fake_override*/ fun isEmpty(): kotlin.Boolean
     public abstract override /*2*/ fun iterator(): kotlin.MutableIterator<E>
     public abstract override /*1*/ fun remove(/*0*/ o: kotlin.Any?): kotlin.Boolean
@@ -1106,8 +1106,8 @@ public interface Range</*0*/ T : kotlin.Comparable<T>> {
 public interface Set</*0*/ out E> : kotlin.Collection<E> {
     public abstract override /*1*/ val size: kotlin.Int
         public abstract override /*1*/ fun <get-size>(): kotlin.Int
-    public abstract override /*1*/ fun contains(/*0*/ o: kotlin.Any?): kotlin.Boolean
-    public abstract override /*1*/ fun containsAll(/*0*/ c: kotlin.Collection<kotlin.Any?>): kotlin.Boolean
+    public abstract override /*1*/ fun contains(/*0*/ o: @kotlin.UnsafeVariance() E): kotlin.Boolean
+    public abstract override /*1*/ fun containsAll(/*0*/ c: kotlin.Collection<@kotlin.UnsafeVariance() E>): kotlin.Boolean
     public abstract override /*1*/ fun isEmpty(): kotlin.Boolean
     public abstract override /*1*/ fun iterator(): kotlin.Iterator<E>
 }
diff --git a/core/builtins/native/kotlin/Collections.kt b/core/builtins/native/kotlin/Collections.kt
index a954886c36c..83ce32c20db 100644
--- a/core/builtins/native/kotlin/Collections.kt
+++ b/core/builtins/native/kotlin/Collections.kt
@@ -59,14 +59,14 @@ public interface Collection<out E> : Iterable<E> {
     /**
      * Checks if the specified element is contained in this collection.
      */
-    public operator fun contains(o: Any?): Boolean
+    public operator fun contains(o: @UnsafeVariance E): Boolean
     override fun iterator(): Iterator<E>
 
     // Bulk Operations
     /**
      * Checks if all elements in the specified collection are contained in this collection.
      */
-    public fun containsAll(c: Collection<Any?>): Boolean
+    public fun containsAll(c: Collection<@UnsafeVariance E>): Boolean
 }
 
 /**
@@ -130,11 +130,11 @@ public interface List<out E> : Collection<E> {
     // Query Operations
     override val size: Int
     override fun isEmpty(): Boolean
-    override fun contains(o: Any?): Boolean
+    override fun contains(o: @UnsafeVariance E): Boolean
     override fun iterator(): Iterator<E>
 
     // Bulk Operations
-    override fun containsAll(c: Collection<Any?>): Boolean
+    override fun containsAll(c: Collection<@UnsafeVariance E>): Boolean
 
     // Positional Access Operations
     /**
@@ -234,11 +234,11 @@ public interface Set<out E> : Collection<E> {
     // Query Operations
     override val size: Int
     override fun isEmpty(): Boolean
-    override fun contains(o: Any?): Boolean
+    override fun contains(o: @UnsafeVariance E): Boolean
     override fun iterator(): Iterator<E>
 
     // Bulk Operations
-    override fun containsAll(c: Collection<Any?>): Boolean
+    override fun containsAll(c: Collection<@UnsafeVariance E>): Boolean
 }
 
 /**