diff --git a/NEWS b/NEWS
index b7a4e8018c..f75c816208 100644
--- a/NEWS
+++ b/NEWS
@@ -86,6 +86,12 @@ sufficient information, see the ChangeLog file or Redmine
 
 [Enumerable]
 
+  [New methods]
+
+    * Enumerable#chain returns an enumerator object that iterates over the
+      elements of the receiver and then those of each argument in sequence.
+      [Feature #15144]
+
   [Modified methods]
 
     * Enumerable#to_h now maps elements to new keys and values by the block if
@@ -95,6 +101,14 @@ sufficient information, see the ChangeLog file or Redmine
 
     * Enumerable#filter is a new alias for Enumerable#select. [Feature #13784]
 
+[Enumerator]
+
+  [New methods]
+
+    * Enumerator#+ returns an enumerator object that iterates over the
+      elements of the receiver and then those of the other operand.
+      [Feature #15144]
+
 [Enumerator::ArithmeticSequence]
 
   * This is a new class to represent a generator of an arithmetic sequence,
@@ -102,6 +116,12 @@ sufficient information, see the ChangeLog file or Redmine
     for representing what is similar to Python's slice. You can get an
     instance of this class from Numeric#step and Range#step.
 
+[Enumerator::Chain]
+
+  * This is a new class to represent a chain of enumerables that works as a
+    single enumerator, generated by such methods as Enumerable#chain and
+    Enumerator#+.
+
 [Enumerator::Lazy]
 
   [Aliased methods]