diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index e149742..084b5f4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,7 @@ jobs:
         os: [ubuntu-latest]
         ruby-version:
           - head
+          - '3.4'
           - '3.3'
           - '3.2'
           - '3.1'
@@ -23,7 +24,7 @@ jobs:
           - os: windows-latest
             ruby-version: head
           - os: windows-latest
-            ruby-version: '3.3'
+            ruby-version: '3.4'
           - os: windows-latest
             ruby-version: mingw
           - os: windows-latest
@@ -33,7 +34,7 @@ jobs:
           - os: macos-latest
             ruby-version: 'head'
           - os: macos-latest
-            ruby-version: '3.3'
+            ruby-version: '3.4'
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v4
diff --git a/.rubocop.yml b/.rubocop.yml
index 6da5969..3db15b9 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -4,7 +4,7 @@
 # https://github.com/bbatsov/rubocop/tree/master/config
 
 AllCops:
-  TargetRubyVersion: 3.3
+  TargetRubyVersion: 3.4
   NewCops: enable
 
 # General
diff --git a/Changelog.md b/Changelog.md
index ec452ef..e61950f 100644
--- a/Changelog.md
+++ b/Changelog.md
@@ -3,6 +3,7 @@
 Below is a complete listing of changes for each revision of HighLine.
 
 ### 3.1.2 / 2025-01-05
+* PR #279 - Upgrades and adjustments for Ruby 3.4 release (@abinoam)
 * PR #278 - Prevent ArgumentError for #col_count_calculate when items exceed 80 chars (@davidjkling, @justintsteele)
 
 ### 3.1.1 / 2024-08-18
diff --git a/Gemfile b/Gemfile
index 15da695..2c9d8e4 100644
--- a/Gemfile
+++ b/Gemfile
@@ -17,4 +17,5 @@ group :code_quality do
   # gem "pronto-poper", require: false, platform: :ruby
   gem "pronto-reek", require: false, platform: :ruby
   gem "pronto-rubocop", require: false, platform: :ruby
+  gem "base64", require: false
 end
diff --git a/lib/highline.rb b/lib/highline.rb
index dc4e344..87615c0 100644
--- a/lib/highline.rb
+++ b/lib/highline.rb
@@ -555,21 +555,26 @@ def get_line_raw_no_echo_mode(question)
     terminal.raw_no_echo_mode_exec do
       loop do
         character = terminal.get_character
-        raise Interrupt if character == "\u0003"
-        break unless character
-        break if ["\n", "\r"].include? character
-
-        # honor backspace and delete
-        if character == "\b" || character == "\u007F"
-          chopped = line.chop!
-          output_erase_char if chopped && question.echo
-        elsif character == "\cU"
+
+        case character
+        when "\u0003" # Ctrl+C (Interrupt)
+          raise Interrupt
+        when nil # No character received
+          break
+        when "\n", "\r" # Newline or carriage return
+          break
+        when "\b", "\u007F" # Backspace and delete
+          unless line.empty?
+            line = line.chop
+            output_erase_char if question.echo
+          end
+        when "\cU" # Clear line
           line.size.times { output_erase_char } if question.echo
           line = ""
-        elsif character == "\e"
+        when "\e" # Escape key
           ignore_arrow_key
-        else
-          line << character
+        else # Any other character
+          line += character
           say_last_char_or_echo_char(line, question)
         end
 
diff --git a/lib/highline/menu.rb b/lib/highline/menu.rb
index 2ae1ad3..36128cf 100644
--- a/lib/highline/menu.rb
+++ b/lib/highline/menu.rb
@@ -374,12 +374,14 @@ def options
     end
 
     def map_items_by_index
-      if [:letter, :capital_letter].include?(@index)
-        # @ and ` are the previous ASCII characters to A and a respectively
-        prev_char = (@index == :capital_letter ? '@' : '`')
-        all_items.map { prev_char.succ!.dup }
+      size = all_items.size
+      case @index
+      when :letter
+        ("a".."z").first(size)
+      when :capital_letter
+        ("A".."Z").first(size)
       else
-        (1..all_items.size).map(&:to_s)
+        (1..size).map(&:to_s)
       end
     end
 
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 32bfcb8..e70a1aa 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -11,12 +11,14 @@
 require "highline/io_console_compatible"
 
 require "highline"
-debug_message = "Tests will be run under:\n"
-debug_message << "  - #{HighLine.new.terminal.class}\n"
-debug_message << "  - HighLine::VERSION #{HighLine::VERSION}\n"
 
-debug_message << "  - #{RUBY_DESCRIPTION}\n" if defined? RUBY_DESCRIPTION
+debug_message = <<~DEBUG_MESSAGE
+  Tests will be run under:
+    - #{HighLine.new.terminal.class}
+    - HighLine::VERSION #{HighLine::VERSION}
+DEBUG_MESSAGE
 
+debug_message += "  - #{RUBY_DESCRIPTION}\n" if defined? RUBY_DESCRIPTION
 puts debug_message
 
 require "minitest/autorun"