diff --git a/libraries/stdlib/src/kotlin/dom/DomJVM.kt b/libraries/stdlib/src/kotlin/dom/DomJVM.kt
index 6dc67a79f8c..06a5d2e2800 100644
--- a/libraries/stdlib/src/kotlin/dom/DomJVM.kt
+++ b/libraries/stdlib/src/kotlin/dom/DomJVM.kt
@@ -165,10 +165,10 @@ public val NodeList.outerHTML: String
     get() = toList().map { it.innerHTML }.join("")
 
 /** Returns an [Iterator] of all the next [Element] siblings */
-public fun Node.nextElements(): List<Element> = nextSiblings().filterIsInstance(javaClass<Element>())
+public fun Node.nextElements(): List<Element> = nextSiblings().filterIsInstance<Element>()
 
 /** Returns an [Iterator] of all the previous [Element] siblings */
-public fun Node.previousElements(): List<Element> = previousSiblings().filterIsInstance(javaClass<Element>())
+public fun Node.previousElements(): List<Element> = previousSiblings().filterIsInstance<Element>()
 
 
 public var Element.classSet: MutableSet<String>
diff --git a/libraries/stdlib/src/kotlin/io/files/Utils.kt b/libraries/stdlib/src/kotlin/io/files/Utils.kt
index 4976ae14390..f94a668d917 100644
--- a/libraries/stdlib/src/kotlin/io/files/Utils.kt
+++ b/libraries/stdlib/src/kotlin/io/files/Utils.kt
@@ -49,7 +49,7 @@ public fun createTempFile(prefix: String = "tmp", suffix: String? = null, direct
  * Returns this if this file is a directory, or the parent if it is a file inside a directory.
  */
 public val File.directory: File
-    get() = if (isDirectory()) this else parent!!
+    get() = if (isDirectory()) this else parentFile!!
 
 /**
  * Returns parent of this abstract path name, or `null` if it has no parent.
diff --git a/libraries/stdlib/src/kotlin/text/CharCategoryJVM.kt b/libraries/stdlib/src/kotlin/text/CharCategoryJVM.kt
index 1c4ba510b29..5989779e3bd 100644
--- a/libraries/stdlib/src/kotlin/text/CharCategoryJVM.kt
+++ b/libraries/stdlib/src/kotlin/text/CharCategoryJVM.kt
@@ -158,7 +158,7 @@ public enum class CharCategory(public val value: Int, public val code: String) {
 
 
     public companion object {
-        private val categoryMap by Delegates.lazy { CharCategory.values().toMap { it.value } }
+        private val categoryMap by lazy { CharCategory.values().toMap { it.value } }
 
         public fun valueOf(category: Int): CharCategory = categoryMap[category] ?: throw IllegalArgumentException("Category #$category is not defined.")
     }
diff --git a/libraries/stdlib/src/kotlin/text/CharDirectionalityJVM.kt b/libraries/stdlib/src/kotlin/text/CharDirectionalityJVM.kt
index 3dd09979e8e..98ca7f421ff 100644
--- a/libraries/stdlib/src/kotlin/text/CharDirectionalityJVM.kt
+++ b/libraries/stdlib/src/kotlin/text/CharDirectionalityJVM.kt
@@ -112,7 +112,7 @@ public enum class CharDirectionality(public val value: Int) {
 
 
     public companion object {
-        private val directionalityMap by Delegates.lazy { CharDirectionality.values().toMap { it.value } }
+        private val directionalityMap by lazy { CharDirectionality.values().toMap { it.value } }
 
         public fun valueOf(directionality: Int): CharDirectionality = directionalityMap[directionality] ?: throw IllegalArgumentException("Directionality #$directionality is not defined.")
     }
diff --git a/libraries/stdlib/test/js/MapJsTest.kt b/libraries/stdlib/test/js/MapJsTest.kt
index d16bdae0eeb..7d77653f8c0 100644
--- a/libraries/stdlib/test/js/MapJsTest.kt
+++ b/libraries/stdlib/test/js/MapJsTest.kt
@@ -21,7 +21,7 @@ class ComplexMapJsTest : MapJsTest() {
         doTest<String>()
     }
 
-    override fun <T : kotlin.Comparable<T>> Collection<T>.toNormalizedList(): List<T> = this.toSortedList()
+    override fun <T : kotlin.Comparable<T>> Collection<T>.toNormalizedList(): List<T> = this.sorted()
     // hashMapOf returns ComlpexHashMap because it is Generic
     override fun emptyMutableMap(): MutableMap<String, Int> = genericHashMapOf()
     override fun emptyMutableMapWithNullableKeyValue(): MutableMap<String?, Int?> = genericHashMapOf()
@@ -39,7 +39,7 @@ class PrimitiveMapJsTest : MapJsTest() {
         assertEquals(VALUES.toNormalizedList(), map.values().toNormalizedList())
     }
 
-    override fun <T : kotlin.Comparable<T>> Collection<T>.toNormalizedList(): List<T> = this.toSortedList()
+    override fun <T : kotlin.Comparable<T>> Collection<T>.toNormalizedList(): List<T> = this.sorted()
     override fun emptyMutableMap(): MutableMap<String, Int> = HashMap()
     override fun emptyMutableMapWithNullableKeyValue(): MutableMap<String?, Int?> = HashMap()
 
diff --git a/libraries/stdlib/test/text/StringJVMTest.kt b/libraries/stdlib/test/text/StringJVMTest.kt
index 3f9f234dfa0..c67958c5dd4 100644
--- a/libraries/stdlib/test/text/StringJVMTest.kt
+++ b/libraries/stdlib/test/text/StringJVMTest.kt
@@ -103,7 +103,7 @@ class StringJVMTest {
         assertTrue {
             data.all { it.isJavaLetter() }
         }
-        assertNot {
+        assertFalse {
             data.all { it.isUpperCase() }
         }
     }
@@ -113,7 +113,7 @@ class StringJVMTest {
         assertTrue {
             data.any() { it.isDigit() }
         }
-        assertNot {
+        assertFalse {
             data.any() { it.isUpperCase() }
         }
     }
@@ -362,7 +362,7 @@ class StringJVMTest {
 
     @test fun orderIgnoringCase() {
         val list = listOf("Beast", "Ast", "asterisk")
-        assertEquals(listOf("Ast", "Beast", "asterisk"), list.sort())
-        assertEquals(listOf("Ast", "asterisk", "Beast"), list.sortBy(String.CASE_INSENSITIVE_ORDER))
+        assertEquals(listOf("Ast", "Beast", "asterisk"), list.sorted())
+        assertEquals(listOf("Ast", "asterisk", "Beast"), list.sortedWith(String.CASE_INSENSITIVE_ORDER))
     }
 }
diff --git a/libraries/tools/kotlin-annotation-processing/src/test/kotlin/org/jetbrains/kotlin/annotation/AnnotationListParseTest.kt b/libraries/tools/kotlin-annotation-processing/src/test/kotlin/org/jetbrains/kotlin/annotation/AnnotationListParseTest.kt
index 23585bea9ff..d1e25afc77f 100644
--- a/libraries/tools/kotlin-annotation-processing/src/test/kotlin/org/jetbrains/kotlin/annotation/AnnotationListParseTest.kt
+++ b/libraries/tools/kotlin-annotation-processing/src/test/kotlin/org/jetbrains/kotlin/annotation/AnnotationListParseTest.kt
@@ -74,8 +74,8 @@ public class AnnotationListParseTest {
             }
         }
 
-        val actualAnnotationsSorted = actualAnnotations.toString().lines().filter { it.isNotEmpty() }.sort()
-        val classDeclarationsSorted = annotationProvider.kotlinClasses.sort()
+        val actualAnnotationsSorted = actualAnnotations.toString().lines().filter { it.isNotEmpty() }.sorted()
+        val classDeclarationsSorted = annotationProvider.kotlinClasses.sorted()
 
         val fileContents = (actualAnnotationsSorted + classDeclarationsSorted).joinToString("\n")
         assertEqualsToFile(expectedFile, fileContents)