diff --git a/libraries/stdlib/src/generated/_Collections.kt b/libraries/stdlib/src/generated/_Collections.kt
index 22ec5a15a18..74576433513 100644
--- a/libraries/stdlib/src/generated/_Collections.kt
+++ b/libraries/stdlib/src/generated/_Collections.kt
@@ -241,6 +241,7 @@ public fun <T> List<T>.getOrNull(index: Int): T? {
  * Returns first index of [element], or -1 if the collection does not contain element.
  */
 public fun <T> Iterable<T>.indexOf(element: T): Int {
+    if (this is List) return this.indexOf(element)
     var index = 0
     for (item in this) {
         if (element == item)
@@ -370,6 +371,7 @@ public inline fun <T> List<T>.last(predicate: (T) -> Boolean): T {
  * Returns last index of [element], or -1 if the collection does not contain element.
  */
 public fun <T> Iterable<T>.lastIndexOf(element: T): Int {
+    if (this is List) return this.lastIndexOf(element)
     var lastIndex = -1
     var index = 0
     for (item in this) {
diff --git a/libraries/tools/kotlin-stdlib-gen/src/templates/Elements.kt b/libraries/tools/kotlin-stdlib-gen/src/templates/Elements.kt
index 8732a83bde1..b2adaae7e95 100644
--- a/libraries/tools/kotlin-stdlib-gen/src/templates/Elements.kt
+++ b/libraries/tools/kotlin-stdlib-gen/src/templates/Elements.kt
@@ -29,8 +29,9 @@ fun elements(): List<GenericFunction> {
         exclude(Strings, Lists) // has native implementation
         doc { "Returns first index of [element], or -1 if the collection does not contain element." }
         returns("Int")
-        body {
+        body { f ->
             """
+            ${if (f == Iterables) "if (this is List) return this.indexOf(element)" else ""}
             var index = 0
             for (item in this) {
                 if (element == item)
@@ -75,8 +76,9 @@ fun elements(): List<GenericFunction> {
         exclude(Strings, Lists) // has native implementation
         doc { "Returns last index of [element], or -1 if the collection does not contain element." }
         returns("Int")
-        body {
+        body { f ->
             """
+            ${if (f == Iterables) "if (this is List) return this.lastIndexOf(element)" else ""}
             var lastIndex = -1
             var index = 0
             for (item in this) {
@@ -521,26 +523,14 @@ fun elements(): List<GenericFunction> {
         doc(Strings) { """"Returns the last character matching the given [predicate].
         @throws [NoSuchElementException] if no such character is found.""" }
         returns("T")
-        body {
-            """
-            var last: T? = null
-            var found = false
-            for (element in this) {
-                if (predicate(element)) {
-                    last = element
-                    found = true
-                }
-            }
-            if (!found) throw NoSuchElementException("Collection doesn't contain any element matching the predicate.")
-            return last as T
-            """
-        }
-
-        body(Iterables) {
+        body { f ->
+            (if (f == Iterables)
             """
             if (this is List)
                 return this.last(predicate)
-
+            """
+            else "") +
+            """
             var last: T? = null
             var found = false
             for (element in this) {
@@ -570,23 +560,14 @@ fun elements(): List<GenericFunction> {
         doc { "Returns the last element matching the given [predicate], or `null` if no such element was found." }
         doc(Strings) { "Returns the last character matching the given [predicate], or `null` if no such character was found." }
         returns("T?")
-        body {
-            """
-            var last: T? = null
-            for (element in this) {
-                if (predicate(element)) {
-                    last = element
-                }
-            }
-            return last
-            """
-        }
-
-        body(Iterables) {
+        body { f ->
+            (if (f == Iterables)
             """
             if (this is List)
                 return this.lastOrNull(predicate)
-
+            """
+            else "") +
+            """
             var last: T? = null
             for (element in this) {
                 if (predicate(element)) {
@@ -597,8 +578,6 @@ fun elements(): List<GenericFunction> {
             """
         }
 
-
-
         body(ArraysOfPrimitives, ArraysOfObjects, Lists) {
             """
             for (index in this.indices.reversed()) {