diff --git a/js/js.libraries/src/core/javaio.kt b/js/js.libraries/src/core/javaio.kt
index fdf2dcd371b..7fc83c39bd0 100644
--- a/js/js.libraries/src/core/javaio.kt
+++ b/js/js.libraries/src/core/javaio.kt
@@ -5,7 +5,7 @@ public class IOException(message: String = "") : Exception() {}
 
 @library
 public interface Closeable {
-    public open fun close(): Unit
+    public fun close(): Unit
 }
 
 interface Serializable
diff --git a/js/js.libraries/src/core/javalang.kt b/js/js.libraries/src/core/javalang.kt
index 35705adb1d9..e00278d70a3 100644
--- a/js/js.libraries/src/core/javalang.kt
+++ b/js/js.libraries/src/core/javalang.kt
@@ -16,10 +16,9 @@
 
 package java.lang
 
-
 @library
 public interface Runnable {
-    public open fun run(): Unit
+    public fun run(): Unit
 }
 
 public fun Runnable(action: () -> Unit): Runnable = object : Runnable {
@@ -28,9 +27,9 @@ public fun Runnable(action: () -> Unit): Runnable = object : Runnable {
 
 @library
 public interface Appendable {
-    public open fun append(csq: CharSequence?): Appendable
-    public open fun append(csq: CharSequence?, start: Int, end: Int): Appendable
-    public open fun append(c: Char): Appendable
+    public fun append(csq: CharSequence?): Appendable
+    public fun append(csq: CharSequence?, start: Int, end: Int): Appendable
+    public fun append(c: Char): Appendable
 }
 
 @library
diff --git a/js/js.libraries/src/core/javautil.kt b/js/js.libraries/src/core/javautil.kt
index acb9b1bb453..1e4c3b9ab27 100644
--- a/js/js.libraries/src/core/javautil.kt
+++ b/js/js.libraries/src/core/javautil.kt
@@ -18,11 +18,11 @@ package java.util
 
 @library
 public interface Comparator<T> {
-    public fun compare(obj1: T, obj2: T): Int
+    public fun compare(a: T, b: T): Int
 }
 
 public inline fun <T> Comparator(crossinline comparison: (T, T) -> Int): Comparator<T> = object : Comparator<T> {
-    override fun compare(obj1: T, obj2: T): Int = comparison(obj1, obj2)
+    override fun compare(a: T, b: T): Int = comparison(a, b)
 }
 
 
diff --git a/js/js.libraries/src/core/kotlin_special.kt b/js/js.libraries/src/core/kotlin_special.kt
index b19dac237a8..592f9a09606 100644
--- a/js/js.libraries/src/core/kotlin_special.kt
+++ b/js/js.libraries/src/core/kotlin_special.kt
@@ -499,7 +499,7 @@ public inline fun <T> Array<out T>.plusElement(element: T): Array<T> {
  */
 @library("primitiveArraySort")
 public fun ByteArray.sort(): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -507,7 +507,7 @@ public fun ByteArray.sort(): Unit {
  */
 @library("primitiveArraySort")
 public fun CharArray.sort(): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -515,7 +515,7 @@ public fun CharArray.sort(): Unit {
  */
 @library("primitiveArraySort")
 public fun DoubleArray.sort(): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -523,7 +523,7 @@ public fun DoubleArray.sort(): Unit {
  */
 @library("primitiveArraySort")
 public fun FloatArray.sort(): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -531,7 +531,7 @@ public fun FloatArray.sort(): Unit {
  */
 @library("primitiveArraySort")
 public fun IntArray.sort(): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -539,7 +539,7 @@ public fun IntArray.sort(): Unit {
  */
 @library("primitiveArraySort")
 public fun ShortArray.sort(): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -563,7 +563,7 @@ public fun LongArray.sort(): Unit {
  */
 @native
 public fun <T> Array<out T>.sort(comparison: (T, T) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -571,7 +571,7 @@ public fun <T> Array<out T>.sort(comparison: (T, T) -> Int): Unit {
  */
 @native
 public fun ByteArray.sort(comparison: (Byte, Byte) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -579,7 +579,7 @@ public fun ByteArray.sort(comparison: (Byte, Byte) -> Int): Unit {
  */
 @native
 public fun CharArray.sort(comparison: (Char, Char) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -587,7 +587,7 @@ public fun CharArray.sort(comparison: (Char, Char) -> Int): Unit {
  */
 @native
 public fun DoubleArray.sort(comparison: (Double, Double) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -595,7 +595,7 @@ public fun DoubleArray.sort(comparison: (Double, Double) -> Int): Unit {
  */
 @native
 public fun FloatArray.sort(comparison: (Float, Float) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -603,7 +603,7 @@ public fun FloatArray.sort(comparison: (Float, Float) -> Int): Unit {
  */
 @native
 public fun IntArray.sort(comparison: (Int, Int) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -611,7 +611,7 @@ public fun IntArray.sort(comparison: (Int, Int) -> Int): Unit {
  */
 @native
 public fun LongArray.sort(comparison: (Long, Long) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
@@ -619,7 +619,7 @@ public fun LongArray.sort(comparison: (Long, Long) -> Int): Unit {
  */
 @native
 public fun ShortArray.sort(comparison: (Short, Short) -> Int): Unit {
-    return noImpl
+    noImpl
 }
 
 /**
diff --git a/libraries/stdlib/src/kotlin/comparisons/Comparisons.kt b/libraries/stdlib/src/kotlin/comparisons/Comparisons.kt
index 84f5c2b435a..6141994958a 100644
--- a/libraries/stdlib/src/kotlin/comparisons/Comparisons.kt
+++ b/libraries/stdlib/src/kotlin/comparisons/Comparisons.kt
@@ -303,13 +303,13 @@ private class ReversedComparator<T>(public val comparator: Comparator<T>): Compa
 }
 
 private object NaturalOrderComparator : Comparator<Comparable<Any>> {
-    override fun compare(c1: Comparable<Any>, c2: Comparable<Any>): Int = c1.compareTo(c2)
+    override fun compare(a: Comparable<Any>, b: Comparable<Any>): Int = a.compareTo(b)
     @Suppress("VIRTUAL_MEMBER_HIDDEN")
     fun reversed(): Comparator<Comparable<Any>> = ReverseOrderComparator
 }
 
 private object ReverseOrderComparator: Comparator<Comparable<Any>> {
-    override fun compare(c1: Comparable<Any>, c2: Comparable<Any>): Int = c2.compareTo(c1)
+    override fun compare(a: Comparable<Any>, b: Comparable<Any>): Int = b.compareTo(a)
     @Suppress("VIRTUAL_MEMBER_HIDDEN")
     fun reversed(): Comparator<Comparable<Any>> = NaturalOrderComparator
 }
diff --git a/libraries/tools/kotlin-stdlib-gen/src/templates/SpecialJS.kt b/libraries/tools/kotlin-stdlib-gen/src/templates/SpecialJS.kt
index 505ba61d3aa..137ce585e92 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/templates/SpecialJS.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/templates/SpecialJS.kt
@@ -171,7 +171,7 @@ fun specialJS(): List<GenericFunction> {
         annotations("@native")
         returns("Unit")
         doc { "Sorts the array in-place according to the order specified by the given [comparison] function." }
-        body { "return noImpl" }
+        body { "noImpl" }
     }
 
     templates add f("sortWith(comparator: Comparator<in T>)") {
@@ -194,7 +194,7 @@ fun specialJS(): List<GenericFunction> {
         returns("Unit")
         doc { "Sorts the array in-place." }
         annotations("""@library("primitiveArraySort")""")
-        body { "return noImpl" }
+        body { "noImpl" }
     }
 
     templates add f("sort()") {