diff --git a/core/io.rbs b/core/io.rbs
index 9ee8110d53..afa04fb6c0 100644
--- a/core/io.rbs
+++ b/core/io.rbs
@@ -3148,8 +3148,8 @@ class IO < Object
   #
   # Returns an Enumerator if no block is given.
   #
-  def each_line: (?String sep, ?Integer limit) { (String line) -> void } -> self
-               | (?String sep, ?Integer limit) -> ::Enumerator[String, self]
+  def each_line: (?String sep, ?Integer limit, ?chomp: boolish) { (String line) -> void } -> self
+               | (?String sep, ?Integer limit, ?chomp: boolish) -> ::Enumerator[String, self]
 
   # <!--
   #   rdoc-file=io.c
diff --git a/core/kernel.rbs b/core/kernel.rbs
index 15892b3065..bf8e2aa7cf 100644
--- a/core/kernel.rbs
+++ b/core/kernel.rbs
@@ -1394,7 +1394,7 @@ module Kernel : BasicObject
   # Optional keyword arguments `enc_opts` specify encoding options; see [Encoding
   # options](rdoc-ref:encodings.rdoc@Encoding+Options).
   #
-  def self?.readlines: (?String arg0, ?Integer arg1) -> ::Array[String]
+  def self?.readlines: (?String arg0, ?Integer arg1, ?chomp: boolish) -> ::Array[String]
 
   # <!--
   #   rdoc-file=lib/rubygems/core_ext/kernel_require.rb