diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index 788cfddc..f4818dc9 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -11,7 +11,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby: [2.7, "3.0", 3.1, 3.2, 3.3]
+        ruby: [2.7, "3.0", 3.1, 3.2, 3.3, "jruby-9.4"]
     runs-on: ubuntu-latest
     env:
       FERRUM_PROCESS_TIMEOUT: 25
diff --git a/lib/ferrum/browser.rb b/lib/ferrum/browser.rb
index 9626ad1d..6613c287 100644
--- a/lib/ferrum/browser.rb
+++ b/lib/ferrum/browser.rb
@@ -9,6 +9,7 @@
 require "ferrum/browser/xvfb"
 require "ferrum/browser/options"
 require "ferrum/browser/process"
+require "ferrum/browser/jruby_process"
 require "ferrum/browser/binary"
 require "ferrum/browser/version_info"
 
@@ -253,7 +254,8 @@ def headless_new?
 
     def start
       Utils::ElapsedTime.start
-      @process = Process.new(options)
+      process_class = Utils::Platform.jruby? ? JrubyProcess : Process
+      @process = process_class.new(options)
 
       begin
         @process.start
diff --git a/lib/ferrum/browser/jruby_process.rb b/lib/ferrum/browser/jruby_process.rb
new file mode 100644
index 00000000..27103373
--- /dev/null
+++ b/lib/ferrum/browser/jruby_process.rb
@@ -0,0 +1,89 @@
+# frozen_string_literal: true
+
+require "ferrum/browser/process"
+
+module Ferrum
+  class Browser
+    class JrubyProcess < Process
+      def start
+        # Don't do anything as browser is already running as external process.
+        return if ws_url
+
+        begin
+          process_builder_args = @command.to_a
+          # Sometimes subprocesses are launched with the wrong architecture on Apple Silicon.
+          if ENV_JAVA["os.name"] == "Mac OS X" && ENV_JAVA["os.arch"] == "aarch64"
+            process_builder_args.unshift("/usr/bin/arch", "-arm64")
+          end
+          process_builder = java.lang.ProcessBuilder.new(*process_builder_args)
+          # unless user directory is on a Windows UNC path
+          process_builder.directory(java.io.File.new(@user_data_dir)) unless @user_data_dir =~ %r{\A//}
+          process_builder.redirectErrorStream(true)
+
+          if @command.xvfb?
+            @xvfb = Xvfb.start(@command.options)
+            ObjectSpace.define_finalizer(self, self.class.process_killer(@xvfb.pid))
+            process_builder.environment.merge! Hash(@xvfb&.to_env)
+          end
+
+          @java_process = process_builder.start
+
+          # The process output is switched to a buffered reader and parsed to get the WebSocket URL.
+          input_reader = java.io.BufferedReader.new(java.io.InputStreamReader.new(java_process.getInputStream))
+          parse_ws_url(input_reader, @process_timeout)
+          parse_json_version(ws_url)
+        end
+      end
+
+      attr_reader :java_process
+
+      def stop
+        destroy_java_process
+
+        remove_user_data_dir if @user_data_dir
+        ObjectSpace.undefine_finalizer(self)
+      end
+
+      private
+
+      def parse_ws_url(read_io, timeout)
+        output = ""
+        start = Utils::ElapsedTime.monotonic_time
+        max_time = start + timeout
+        regexp = %r{DevTools listening on (ws://.*[a-zA-Z0-9-]{36})}
+        while Utils::ElapsedTime.monotonic_time < max_time
+          # The buffered reader is used to read the process output.
+          if output.match(regexp)
+            self.ws_url = output.match(regexp)[1].strip
+            break
+          elsif (rl = read_io.read_line)
+            output += rl
+          end
+        end
+
+        return if ws_url
+
+        @logger&.puts(output)
+        raise ProcessTimeoutError.new(timeout, output)
+      end
+
+      def destroy_java_process
+        return unless java_process
+
+        java_process.destroy
+        retry_times = 6
+        while java_process.isAlive && retry_times.positive?
+          sleep 1
+          retry_times -= 1
+        end
+        if java_process.isAlive
+          @logger&.puts("Ferrum::Browser::JrubyProcess is still alive, killing it forcibly")
+          java_process.destroyForcibly
+        else
+          @logger&.puts("Ferrum::Browser::JrubyProcess is stopped")
+        end
+        @java_process = nil
+      end
+    end
+  end
+end
diff --git a/lib/ferrum/browser/process.rb b/lib/ferrum/browser/process.rb
index 7ca321ef..9940d39c 100644
--- a/lib/ferrum/browser/process.rb
+++ b/lib/ferrum/browser/process.rb
@@ -180,7 +180,7 @@ def close_io(*ios)
         ios.each do |io|
           io.close unless io.closed?
         rescue IOError
-          raise unless RUBY_ENGINE == "jruby"
+          raise unless Utils::Platform.jruby?
         end
       end
 
diff --git a/lib/ferrum/client.rb b/lib/ferrum/client.rb
index de0732f5..676a8b0c 100644
--- a/lib/ferrum/client.rb
+++ b/lib/ferrum/client.rb
@@ -62,7 +62,7 @@ class Client
     attr_reader :ws_url, :options, :subscriber
 
     def initialize(ws_url, options)
-      @command_id = 0
+      @command_id = Concurrent::AtomicFixnum.new(0)
       @ws_url = ws_url
       @options = options
       @pendings = Concurrent::Hash.new
@@ -131,7 +131,7 @@ def build_message(method, params)
     private
 
     def start
-      @thread = Utils::Thread.spawn do
+      @thread = Utils::Thread.spawn(abort_on_exception: !Utils::Platform.jruby?) do
         loop do
           message = @ws.messages.pop
           break unless message
@@ -141,12 +141,14 @@ def start
           else
             @pendings[message["id"]]&.set(message)
           end
+        rescue StandardError => e
+          @logger&.puts("Ferrum::Client thread raised an exception #{e.class.name}: #{e.message}")
         end
       end
     end
 
     def next_command_id
-      @command_id += 1
+      @command_id.increment
     end
 
     def raise_browser_error(error)
diff --git a/lib/ferrum/client/web_socket.rb b/lib/ferrum/client/web_socket.rb
index e88d73bc..25f27ca1 100644
--- a/lib/ferrum/client/web_socket.rb
+++ b/lib/ferrum/client/web_socket.rb
@@ -93,14 +93,14 @@ def close
       private
 
       def start
-        @thread = Utils::Thread.spawn do
+        @thread = Utils::Thread.spawn(abort_on_exception: !Utils::Platform.jruby?) do
           loop do
             data = @sock.readpartial(512)
             break unless data
 
             @driver.parse(data)
           end
-        rescue EOFError, Errno::ECONNRESET, Errno::EPIPE, IOError # rubocop:disable Lint/ShadowedException
+        rescue EOFError, Errno::ECONNRESET, Errno::EPIPE, Errno::EBADF, IOError # rubocop:disable Lint/ShadowedException
           @messages.close
         end
       end
diff --git a/lib/ferrum/utils/platform.rb b/lib/ferrum/utils/platform.rb
index a38b0622..1530c689 100644
--- a/lib/ferrum/utils/platform.rb
+++ b/lib/ferrum/utils/platform.rb
@@ -27,6 +27,10 @@ def mac_arm?
       def mri?
         defined?(RUBY_ENGINE) && RUBY_ENGINE == "ruby"
       end
+
+      def jruby?
+        defined?(JRUBY_VERSION)
+      end
     end
   end
 end
diff --git a/spec/browser_spec.rb b/spec/browser_spec.rb
index 0e0c944a..527adc79 100644
--- a/spec/browser_spec.rb
+++ b/spec/browser_spec.rb
@@ -364,14 +364,28 @@
       browser&.quit
     end
 
-    it "supports stopping the session", skip: Ferrum::Utils::Platform.windows? do
-      browser = Ferrum::Browser.new
-      pid = browser.process.pid
+    context "for MRI Ruby", skip: Ferrum::Utils::Platform.windows? || Ferrum::Utils::Platform.jruby? do
+      it "supports stopping the session" do
+        browser = Ferrum::Browser.new
+        pid = browser.process.pid
+
+        expect(Process.kill(0, pid)).to eq(1)
+        browser.quit
 
-      expect(Process.kill(0, pid)).to eq(1)
-      browser.quit
+        expect { Process.kill(0, pid) }.to raise_error(Errno::ESRCH)
+      end
+    end
 
-      expect { Process.kill(0, pid) }.to raise_error(Errno::ESRCH)
+    context "for JRuby", skip: Ferrum::Utils::Platform.windows? || Ferrum::Utils::Platform.mri? do
+      it "supports stopping the session" do
+        browser = Ferrum::Browser.new
+        pid = browser.process.java_process.pid
+
+        expect(Process.kill(0, pid)).to eq(1)
+        browser.quit
+
+        expect { Process.kill(0, pid) }.to raise_error(Errno::ESRCH)
+      end
     end
   end
 
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 9f94527b..c4a83d16 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -47,6 +47,8 @@
 
   config.after(:all) do
     @browser.quit
+  rescue IOError => e
+    puts "#{e.class}: #{e.message}"
   end
 
   config.before(:each) do
diff --git a/spec/unit/process_spec.rb b/spec/unit/process_spec.rb
index 5ad6c435..3ca91e8e 100644
--- a/spec/unit/process_spec.rb
+++ b/spec/unit/process_spec.rb
@@ -3,7 +3,7 @@
 describe Ferrum::Browser::Process do
   subject { Ferrum::Browser.new(port: 6000, host: "127.0.0.1") }
 
-  unless Ferrum::Utils::Platform.windows?
+  unless Ferrum::Utils::Platform.windows? || Ferrum::Utils::Platform.jruby?
     it "forcibly kills the child if it does not respond to SIGTERM" do
       allow(Process).to receive(:spawn).and_return(5678)
       allow(Process).to receive(:wait).and_return(nil)