diff --git a/.github/workflows/push_gem.yml b/.github/workflows/push_gem.yml
index 847493f..de54a5b 100644
--- a/.github/workflows/push_gem.yml
+++ b/.github/workflows/push_gem.yml
@@ -23,24 +23,24 @@ jobs:
 
     steps:
       - name: Harden Runner
-        uses: step-security/harden-runner@4d991eb9b905ef189e4c376166672c3f2f230481 # v2.11.0
+        uses: step-security/harden-runner@58077d3c7e43986b6b15fba718e8ea69e387dfcc # v2.15.1
         with:
           egress-policy: audit
 
-      - uses: actions/checkout@0ad4b8fadaa221de15dcec353f45205ec38ea70b # v4.1.4
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3 # v6.0.0
 
       - name: Set up Ruby
-        uses: ruby/setup-ruby@a6e6f86333f0a2523ece813039b8b4be04560854 # v1.190.0
+        uses: ruby/setup-ruby@d5126b9b3579e429dd52e51e68624dda2e05be25 # v1.267.0
         with:
           bundler-cache: true
           ruby-version: ruby
 
       - name: Publish to RubyGems
-        uses: rubygems/release-gem@a25424ba2ba8b387abc8ef40807c2c85b96cbe32 # v1.1.1
+        uses: rubygems/release-gem@e9a6361a0b14562539327c2a02373edc56dd3169 # v1.1.4
 
       - name: Create GitHub release
         run: |
           tag_name="$(git describe --tags --abbrev=0)"
           gh release create "${tag_name}" --verify-tag --generate-notes
         env:
-          GITHUB_TOKEN: ${{ secrets.MATZBOT_GITHUB_WORKFLOW_TOKEN }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index ad325f0..73a7361 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -25,7 +25,7 @@ jobs:
             os: windows-latest
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Ruby
       uses: ruby/setup-ruby@v1
       with:
diff --git a/Gemfile b/Gemfile
index ba909e8..723b810 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,6 +5,7 @@ gemspec
 group :development do
   gem "bundler"
   gem "rake"
+  gem "rdoc"
   gem "test-unit"
   gem "test-unit-ruby-core"
 end
diff --git a/lib/logger.rb b/lib/logger.rb
index 25e2c27..be00457 100644
--- a/lib/logger.rb
+++ b/lib/logger.rb
@@ -545,6 +545,7 @@ def fatal!; self.level = FATAL; end
   #   new entries are appended.
   # - An IO stream (typically <tt>$stdout</tt>, <tt>$stderr</tt>. or
   #   an open file): entries are to be written to the given stream.
+  # - An instance of Logger::LogDevice, such as the #logdev of another Logger.
   # - +nil+ or +File::NULL+: no entries are to be written.
   #
   # Argument +shift_age+ must be one of:
@@ -591,11 +592,14 @@ def fatal!; self.level = FATAL; end
   # - +reraise_write_errors+: An array of exception classes, which will
   #   be reraised if there is an error when writing to the log device.
   #   The default is to swallow all exceptions raised.
+  # - +skip_header+: If +true+, prevents the logger from writing a header
+  #   when creating a new log file. The default is +false+, meaning
+  #   the header will be written as usual.
   #
   def initialize(logdev, shift_age = 0, shift_size = 1048576, level: DEBUG,
                  progname: nil, formatter: nil, datetime_format: nil,
                  binmode: false, shift_period_suffix: '%Y%m%d',
-                 reraise_write_errors: [])
+                 reraise_write_errors: [], skip_header: false)
     self.level = level
     self.progname = progname
     @default_formatter = Formatter.new
@@ -603,15 +607,28 @@ def initialize(logdev, shift_age = 0, shift_size = 1048576, level: DEBUG,
     self.formatter = formatter
     @logdev = nil
     @level_override = {}
-    if logdev && logdev != File::NULL
+    return unless logdev
+    case logdev
+    when File::NULL
+      # null logger
+    when LogDevice
+      @logdev = logdev
+    else
       @logdev = LogDevice.new(logdev, shift_age: shift_age,
         shift_size: shift_size,
         shift_period_suffix: shift_period_suffix,
         binmode: binmode,
-        reraise_write_errors: reraise_write_errors)
+        reraise_write_errors: reraise_write_errors,
+        skip_header: skip_header)
     end
   end
 
+  # The underlying log device.
+  #
+  # This is the first argument passed to the constructor, wrapped in a
+  # Logger::LogDevice, along with the binmode flag and rotation options.
+  attr_reader :logdev
+
   # Sets the logger's output stream:
   #
   # - If +logdev+ is +nil+, reopens the current output stream.
diff --git a/lib/logger/log_device.rb b/lib/logger/log_device.rb
index cde3158..e16f3b7 100644
--- a/lib/logger/log_device.rb
+++ b/lib/logger/log_device.rb
@@ -11,10 +11,14 @@ class LogDevice
     attr_reader :filename
     include MonitorMixin
 
-    def initialize(log = nil, shift_age: nil, shift_size: nil, shift_period_suffix: nil, binmode: false, reraise_write_errors: [])
+    def initialize(
+      log = nil, shift_age: nil, shift_size: nil, shift_period_suffix: nil,
+      binmode: false, reraise_write_errors: [], skip_header: false
+    )
       @dev = @filename = @shift_age = @shift_size = @shift_period_suffix = nil
       @binmode = binmode
       @reraise_write_errors = reraise_write_errors
+      @skip_header = skip_header
       mon_initialize
       set_dev(log)
       set_file(shift_age, shift_size, shift_period_suffix) if @filename
@@ -132,7 +136,7 @@ def create_logfile(filename)
         logdev = fixup_mode(logdev)
         logdev.sync = true
         logdev.binmode if @binmode
-        add_log_header(logdev)
+        add_log_header(logdev) unless @skip_header
         logdev.flock(File::LOCK_UN)
         logdev
       rescue Errno::EEXIST
diff --git a/lib/logger/version.rb b/lib/logger/version.rb
index 463be13..0d74bec 100644
--- a/lib/logger/version.rb
+++ b/lib/logger/version.rb
@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 class Logger
-  VERSION = "1.6.6"
+  VERSION = "1.7.0"
 end
diff --git a/test/logger/test_logdevice.rb b/test/logger/test_logdevice.rb
index c9b0816..f8350df 100644
--- a/test/logger/test_logdevice.rb
+++ b/test/logger/test_logdevice.rb
@@ -502,6 +502,12 @@ def test_shifting_age_in_multiprocess
     end
   end
 
+  def test_open_without_header
+    d(@filename, skip_header: true)
+
+    assert_equal("", File.read(@filename))
+  end
+
   def test_open_logfile_in_multiprocess
     tmpfile = Tempfile.new([File.basename(__FILE__, '.*'), '_1.log'])
     logfile = tmpfile.path
@@ -739,7 +745,7 @@ class << Time
 
   def test_shifting_weekly_dst_change
     Dir.mktmpdir do |tmpdir|
-      assert_separately([{"TZ"=>"Europe/London"}, *%W"-I#{@top_dir} -rlogger -C#{tmpdir} -"], "#{<<-"begin;"}\n#{<<-'end;'}")
+      assert_separately([{"TZ"=>"Europe/London"}, *%W"-I#{@top_dir} -W0 -rlogger -C#{tmpdir} -"], "#{<<-"begin;"}\n#{<<-'end;'}")
       begin;
         begin
           module FakeTime
@@ -770,7 +776,7 @@ class << Time
 
   def test_shifting_monthly_dst_change
     Dir.mktmpdir do |tmpdir|
-      assert_separately([{"TZ"=>"Europe/London"}, *%W"-I#{@top_dir} -rlogger -C#{tmpdir} -"], "#{<<-"begin;"}\n#{<<-'end;'}")
+      assert_separately([{"TZ"=>"Europe/London"}, *%W"-I#{@top_dir} -W0 -rlogger -C#{tmpdir} -"], "#{<<-"begin;"}\n#{<<-'end;'}")
       begin;
         begin
           module FakeTime
diff --git a/test/logger/test_logger.rb b/test/logger/test_logger.rb
index ea27fba..75a0f74 100644
--- a/test/logger/test_logger.rb
+++ b/test/logger/test_logger.rb
@@ -177,6 +177,16 @@ def test_initialize
     assert_nil(logger.datetime_format)
   end
 
+  def test_logdev
+    logger = Logger.new(STDERR)
+    assert_instance_of(Logger::LogDevice, logger.logdev)
+
+    logdev = Logger::LogDevice.new(STDERR)
+    logger = Logger.new(logdev)
+    assert_instance_of(Logger::LogDevice, logger.logdev)
+    assert_equal(STDERR, logger.logdev.dev)
+  end
+
   def test_initialize_with_level
     # default
     logger = Logger.new(STDERR)