diff --git a/libraries/stdlib/test/collections/CollectionTest.kt b/libraries/stdlib/test/collections/CollectionTest.kt
index 9d9070fb2ef..157823ba7f7 100644
--- a/libraries/stdlib/test/collections/CollectionTest.kt
+++ b/libraries/stdlib/test/collections/CollectionTest.kt
@@ -433,7 +433,7 @@ class CollectionTest {
 
         // lists throw an exception if out of range
         assertFails {
-            assertEquals(null, list[2])
+            val outOfBounds = list[2]
         }
 
         // lets try update the list
diff --git a/libraries/stdlib/test/collections/IterableTests.kt b/libraries/stdlib/test/collections/IterableTests.kt
index a25a22724c3..d0ea310aa44 100644
--- a/libraries/stdlib/test/collections/IterableTests.kt
+++ b/libraries/stdlib/test/collections/IterableTests.kt
@@ -356,16 +356,16 @@ abstract class IterableTests<T : Iterable<String>>(val data: T, val empty: T) {
         // lets use a mutable variable
         var result: Iterable<String> = data
         result -= "foo"
-        assertEquals(listOf("bar"), result)
+        assertEquals(listOf("bar"), result as? List)
         result = data
         result -= listOf("beer", "bar")
-        assertEquals(listOf("foo"), result)
+        assertEquals(listOf("foo"), result as? List)
         result = data
         result -= arrayOf("bar", "foo")
-        assertEquals(emptyList<String>(), result)
+        assertEquals(emptyList<String>(), result as? List)
         result = data
         result -= sequenceOf("foo", "g")
-        assertEquals(listOf("bar"), result)
+        assertEquals(listOf("bar"), result as? List)
     }
 
 }
diff --git a/libraries/stdlib/test/js/MapJsTest.kt b/libraries/stdlib/test/js/MapJsTest.kt
index 7d77653f8c0..de7db87ca25 100644
--- a/libraries/stdlib/test/js/MapJsTest.kt
+++ b/libraries/stdlib/test/js/MapJsTest.kt
@@ -14,9 +14,10 @@ class ComplexMapJsTest : MapJsTest() {
         HashMap<K, Int>(3, 0.5f)
         val map = HashMap<K, Int>(createTestMap() as HashMap<K, Int>)
 
-        assertEquals(KEYS.toNormalizedList(), map.keySet().toNormalizedList())
-        assertEquals(VALUES.toNormalizedList(), map.values().toNormalizedList())
+        assertEquals(KEYS.toNormalizedList(), map.keys.toNormalizedList() as List<Any>)
+        assertEquals(VALUES.toNormalizedList(), map.values.toNormalizedList())
     }
+
     @test override fun constructors() {
         doTest<String>()
     }
@@ -35,8 +36,8 @@ class PrimitiveMapJsTest : MapJsTest() {
 
         val map = HashMap<String, Int>(createTestMap())
 
-        assertEquals(KEYS.toNormalizedList(), map.keySet().toNormalizedList())
-        assertEquals(VALUES.toNormalizedList(), map.values().toNormalizedList())
+        assertEquals(KEYS.toNormalizedList(), map.keys.toNormalizedList())
+        assertEquals(VALUES.toNormalizedList(), map.values.toNormalizedList())
     }
 
     override fun <T : kotlin.Comparable<T>> Collection<T>.toNormalizedList(): List<T> = this.sorted()
@@ -62,8 +63,8 @@ class LinkedHashMapTest : MapJsTest() {
 
         val map = LinkedHashMap<String, Int>(createTestMap())
 
-        assertEquals(KEYS.toNormalizedList(), map.keySet().toNormalizedList())
-        assertEquals(VALUES.toNormalizedList(), map.values().toNormalizedList())
+        assertEquals(KEYS.toNormalizedList(), map.keys.toNormalizedList())
+        assertEquals(VALUES.toNormalizedList(), map.values.toNormalizedList())
     }
 
     override fun <T : kotlin.Comparable<T>> Collection<T>.toNormalizedList(): List<T> = this.toList()