diff --git a/.github/CONTRIBUTING.md b/.github/CONTRIBUTING.md
index a865b48b3..0f6450e5c 100644
--- a/.github/CONTRIBUTING.md
+++ b/.github/CONTRIBUTING.md
@@ -66,7 +66,7 @@ There are a few guidelines which we follow when adding features. Consider that s
 
 #### Write Documentation
 
-Document any external behavior in the [README](README.md).
+Document any external behavior in the [README](../README.md).
 
 #### Commit Changes
 
@@ -106,7 +106,7 @@ git push origin my-feature-branch -f
 
 #### Update CHANGELOG
 
-Update the [CHANGELOG](CHANGELOG.md) with a description of what you have changed.
+Update the [CHANGELOG](../CHANGELOG.md) with a description of what you have changed.
 
 #### Check on Your Pull Request
 
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index ab1d23db8..b5724f575 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -6,16 +6,17 @@ concurrency:
 
 jobs:
   build:
+    name: "Tests: Ruby ${{ matrix.ruby }} - ${{ matrix.os }}"
     runs-on: ${{ matrix.os }}-latest
     timeout-minutes: 10
 
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.3, 2.4, 2.5, 2.6, 2.7, '3.0', 3.1, 3.2, 3.3, jruby, truffleruby]
+        ruby: [2.3, 2.4, 2.5, 2.6, 2.7, '3.0', 3.1, 3.2, 3.3, 3.4, jruby, truffleruby]
         os: [ubuntu]
         include:
-          - ruby: 3.3
+          - ruby: ruby
             os: windows
 
     env:
@@ -23,10 +24,9 @@ jobs:
       RUBYOPT: '-w'
       JRUBY_OPTS: '--dev'
 
-    name: "Tests: Ruby ${{ matrix.ruby }} - ${{ matrix.os }}"
     steps:
     - name: Clone Repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
     - name: Setup Ruby ${{ matrix.ruby }}
       uses: ruby/setup-ruby@v1
       with:
@@ -35,6 +35,21 @@ jobs:
     - name: Run tests
       run: bundle exec rake ci
 
+  no-extensions:
+    name: "Test without C extension"
+    runs-on: ubuntu-latest
+    timeout-minutes: 10
+    env:
+      RUBYOPT: '-w'
+    steps:
+    - uses: actions/checkout@v5
+    - uses: ruby/setup-ruby@v1
+      with:
+        ruby-version: ruby
+        bundler-cache: true
+    - name: Run tests
+      run: bundle exec rake spec:ci
+
   isolated:
     name: "Test isolated"
     runs-on: ubuntu-latest
@@ -46,7 +61,7 @@ jobs:
     env:
       RUBYOPT: '-w'
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
       - uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 780f0741c..2ed493ffb 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -18,7 +18,7 @@ jobs:
     env:
       BUNDLE_WITH: "documentation"
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@v5
         with:
           fetch-depth: 0
       - uses: ruby/setup-ruby@v1
@@ -29,7 +29,7 @@ jobs:
       - run: ruby support/generate_docs.rb
 
       - name: Upload artifact
-        uses: actions/upload-pages-artifact@v3
+        uses: actions/upload-pages-artifact@v4
         with:
           path: docs
 
diff --git a/.github/workflows/experimental.yml b/.github/workflows/experimental.yml
index 28048747c..d31d54be9 100644
--- a/.github/workflows/experimental.yml
+++ b/.github/workflows/experimental.yml
@@ -21,7 +21,7 @@ jobs:
     name: "Tests: Experimental Ruby ${{ matrix.ruby }}"
     steps:
     - name: Clone Repo
-      uses: actions/checkout@v4
+      uses: actions/checkout@v5
     - name: Setup Ruby ${{ matrix.ruby }}
       uses: ruby/setup-ruby@v1
       with:
diff --git a/README.md b/README.md
index 63ee743c5..6635e815a 100644
--- a/README.md
+++ b/README.md
@@ -207,7 +207,7 @@ Deprecated features are still available and bugs are being fixed, but new featur
 These are available in the `concurrent-ruby-edge` companion gem.
 
 These features are under active development and may change frequently. They are expected not to
-keep backward compatibility (there may also lack tests and documentation). Semantic versions will
+keep backward compatibility (they may also lack tests and documentation). Semantic versions will
 be obeyed though. Features developed in `concurrent-ruby-edge` are expected to move to
 `concurrent-ruby` when final.
 
@@ -358,7 +358,8 @@ best practice is to depend on `concurrent-ruby` and let users to decide if they
 * Recent CRuby
 * JRuby, `rbenv install jruby-9.2.17.0`
 * Set env variable `CONCURRENT_JRUBY_HOME` to point to it, e.g. `/usr/local/opt/rbenv/versions/jruby-9.2.17.0`
-* Install Docker, required for Windows builds
+* Install Docker or Podman, required for Windows builds
+* If `bundle config get path` is set, use `bundle config set --local path.system true` otherwise the `gem name, path: '.'` gems won't be found (Bundler limitation).
 
 ### Publishing the Gem
 
diff --git a/lib/concurrent-ruby/concurrent/atomic/lock_local_var.rb b/lib/concurrent-ruby/concurrent/atomic/lock_local_var.rb
index ebf23a241..c367d2622 100644
--- a/lib/concurrent-ruby/concurrent/atomic/lock_local_var.rb
+++ b/lib/concurrent-ruby/concurrent/atomic/lock_local_var.rb
@@ -6,6 +6,7 @@ module Concurrent
   # @!visibility private
   def self.mutex_owned_per_thread?
     return false if Concurrent.on_jruby? || Concurrent.on_truffleruby?
+    return RUBY_VERSION < "3.0" if Concurrent.on_cruby?
 
     mutex = Mutex.new
     # Lock the mutex:
diff --git a/lib/concurrent-ruby/concurrent/mvar.rb b/lib/concurrent-ruby/concurrent/mvar.rb
index dfc41950c..9777ba347 100644
--- a/lib/concurrent-ruby/concurrent/mvar.rb
+++ b/lib/concurrent-ruby/concurrent/mvar.rb
@@ -9,7 +9,7 @@ module Concurrent
   # queue of length one, or a special kind of mutable variable.
   #
   # On top of the fundamental `#put` and `#take` operations, we also provide a
-  # `#mutate` that is atomic with respect to operations on the same instance.
+  # `#modify` that is atomic with respect to operations on the same instance.
   # These operations all support timeouts.
   #
   # We also support non-blocking operations `#try_put!` and `#try_take!`, a
@@ -87,7 +87,7 @@ def borrow(timeout = nil)
       @mutex.synchronize do
         wait_for_full(timeout)
 
-        # if we timeoud out we'll still be empty
+        # If we timed out we'll still be empty
         if unlocked_full?
           yield @value
         else
@@ -116,10 +116,10 @@ def put(value, timeout = nil)
     end
 
     # Atomically `take`, yield the value to a block for transformation, and then
-    # `put` the transformed value. Returns the transformed value. A timeout can
+    # `put` the transformed value. Returns the pre-transform value. A timeout can
     # be set to limit the time spent blocked, in which case it returns `TIMEOUT`
     # if the time is exceeded.
-    # @return [Object] the transformed value, or `TIMEOUT`
+    # @return [Object] the pre-transform value, or `TIMEOUT`
     def modify(timeout = nil)
       raise ArgumentError.new('no block given') unless block_given?
 
diff --git a/lib/concurrent-ruby/concurrent/promise.rb b/lib/concurrent-ruby/concurrent/promise.rb
index c717f9b0d..8df80b0c7 100644
--- a/lib/concurrent-ruby/concurrent/promise.rb
+++ b/lib/concurrent-ruby/concurrent/promise.rb
@@ -167,7 +167,7 @@ module Concurrent
   # c2 = p.then(-> reason { raise 'Boom!' })
   #
   # c1.wait.state  #=> :fulfilled
-  # c1.value       #=> 45
+  # c1.value       #=> 42
   # c2.wait.state  #=> :rejected
   # c2.reason      #=> #<RuntimeError: Boom!>
   # ```
diff --git a/spec/concurrent/atomic/atomic_boolean_spec.rb b/spec/concurrent/atomic/atomic_boolean_spec.rb
index 133b7f2ce..76edd3e27 100644
--- a/spec/concurrent/atomic/atomic_boolean_spec.rb
+++ b/spec/concurrent/atomic/atomic_boolean_spec.rb
@@ -142,7 +142,7 @@ module Concurrent
     end
   end
 
-  if Concurrent.allow_c_extensions?
+  if Concurrent.c_extensions_loaded?
     RSpec.describe CAtomicBoolean do
       it_should_behave_like :atomic_boolean
     end
@@ -165,7 +165,7 @@ module Concurrent
       it 'inherits from JavaAtomicBoolean' do
         expect(AtomicBoolean.ancestors).to include(JavaAtomicBoolean)
       end
-    elsif Concurrent.allow_c_extensions?
+    elsif Concurrent.c_extensions_loaded?
       it 'inherits from CAtomicBoolean' do
         expect(AtomicBoolean.ancestors).to include(CAtomicBoolean)
       end
diff --git a/spec/concurrent/atomic/atomic_fixnum_spec.rb b/spec/concurrent/atomic/atomic_fixnum_spec.rb
index 39259b13f..8222bf523 100644
--- a/spec/concurrent/atomic/atomic_fixnum_spec.rb
+++ b/spec/concurrent/atomic/atomic_fixnum_spec.rb
@@ -204,7 +204,7 @@ module Concurrent
     end
   end
 
-  if Concurrent.allow_c_extensions?
+  if Concurrent.c_extensions_loaded?
     RSpec.describe CAtomicFixnum do
       it_should_behave_like :atomic_fixnum
     end
@@ -227,7 +227,7 @@ module Concurrent
       it 'inherits from JavaAtomicFixnum' do
         expect(AtomicFixnum.ancestors).to include(JavaAtomicFixnum)
       end
-    elsif Concurrent.allow_c_extensions?
+    elsif Concurrent.c_extensions_loaded?
       it 'inherits from CAtomicFixnum' do
         expect(AtomicFixnum.ancestors).to include(CAtomicFixnum)
       end
diff --git a/spec/concurrent/atomic/atomic_reference_spec.rb b/spec/concurrent/atomic/atomic_reference_spec.rb
index 2cc0caada..7eaf2e55e 100644
--- a/spec/concurrent/atomic/atomic_reference_spec.rb
+++ b/spec/concurrent/atomic/atomic_reference_spec.rb
@@ -163,7 +163,7 @@ module Concurrent
     it_should_behave_like :atomic_reference
   end
 
-  if Concurrent.allow_c_extensions?
+  if Concurrent.c_extensions_loaded?
     RSpec.describe CAtomicReference do
       it_should_behave_like :atomic_reference
     end
@@ -190,7 +190,7 @@ module Concurrent
       it 'inherits from JavaAtomicReference' do
         expect(described_class.ancestors).to include(Concurrent::JavaAtomicReference)
       end
-    elsif Concurrent.allow_c_extensions?
+    elsif Concurrent.c_extensions_loaded?
       it 'inherits from CAtomicReference' do
         expect(described_class.ancestors).to include(Concurrent::CAtomicReference)
       end