diff --git a/.github/workflows/protocol.yml b/.github/workflows/protocol.yml
index b2889aab1..4225bd934 100644
--- a/.github/workflows/protocol.yml
+++ b/.github/workflows/protocol.yml
@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['2.6', '2.7', '3.0', '3.1', 'head', 'debug']
+        ruby-version: ["2.7", "3.0", "3.1", "head", "debug"]
 
     steps:
     - uses: actions/checkout@v4
diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index a41da836a..8f8685665 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -21,7 +21,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['2.6', '2.7', '3.0', '3.1', '3.2', 'head', 'debug']
+        ruby-version: ["2.7", "3.0", "3.1", "3.2", "head", "debug"]
 
     steps:
     - uses: actions/checkout@v4
diff --git a/debug.gemspec b/debug.gemspec
index 4dc71a826..03ed0584f 100644
--- a/debug.gemspec
+++ b/debug.gemspec
@@ -10,7 +10,7 @@ Gem::Specification.new do |spec|
   spec.description   = %q{Debugging functionality for Ruby. This is completely rewritten debug.rb which was contained by the ancient Ruby versions.}
   spec.homepage      = "https://github.com/ruby/debug"
   spec.licenses      = ["Ruby", "BSD-2-Clause"]
-  spec.required_ruby_version = Gem::Requirement.new(">= 2.6.0")
+  spec.required_ruby_version = Gem::Requirement.new(">= 2.7.0")
 
   spec.metadata["homepage_uri"] = spec.homepage
   spec.metadata["source_code_uri"] = spec.homepage