diff --git a/NEWS.md b/NEWS.md
index 8c6e353ae5..495a633102 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -82,13 +82,6 @@ sufficient information, see the ChangeLog file or Redmine
   class variable from the toplevel scope is now a RuntimeError.
   [[Bug #14541]]
 
-* Rightward assignment statement is added.  [EXPERIMENTAL]
-  [[Feature #15921]]
-
-    ```ruby
-    fib(10) => x
-    ```
-
 * Endless method definition is added.  [EXPERIMENTAL]
   [[Feature #16746]]
 
diff --git a/test/ruby/test_syntax.rb b/test/ruby/test_syntax.rb
index 9f8c4600c6..73c15f8a7f 100644
--- a/test/ruby/test_syntax.rb
+++ b/test/ruby/test_syntax.rb
@@ -1712,16 +1712,6 @@ eom
     assert_equal [[4, 1, 5, 2, 3], {a: 1}], obj.foo(4, 5, 2, 3, a: 1){|args, kws| [args, kws]}
   end
 
-  def test_rightward_assign
-    a = b = nil
-    EnvUtil.suppress_warning {eval("1 => a")}
-    assert_equal(1, a)
-    EnvUtil.suppress_warning {eval("13.divmod(5) => [a,b]")}
-    assert_equal([2,3], [a, b])
-    EnvUtil.suppress_warning {eval("1+2 => a")}
-    assert_equal(3, a)
-  end
-
   private
 
   def not_label(x) @result = x; @not_label ||= nil end