diff --git a/lib/puppeteer/launcher/chrome.rb b/lib/puppeteer/launcher/chrome.rb
index 102fe0fd..905940cd 100644
--- a/lib/puppeteer/launcher/chrome.rb
+++ b/lib/puppeteer/launcher/chrome.rb
@@ -34,7 +34,7 @@ def launch(options = {})
         if @launch_options.pipe?
           chrome_arguments << '--remote-debugging-pipe'
         else
-          chrome_arguments << '--remote-debugging-port=0'
+          chrome_arguments << "--remote-debugging-port=#{@chrome_arg_options.debugging_port}"
         end
       end
 
diff --git a/lib/puppeteer/launcher/chrome_arg_options.rb b/lib/puppeteer/launcher/chrome_arg_options.rb
index 093e8436..907b64be 100644
--- a/lib/puppeteer/launcher/chrome_arg_options.rb
+++ b/lib/puppeteer/launcher/chrome_arg_options.rb
@@ -34,9 +34,10 @@ def initialize(options)
       if @headless.nil?
         @headless = !@devtools
       end
+      @debugging_port = options[:debugging_port] || 0
     end
 
-    attr_reader :args, :user_data_dir
+    attr_reader :args, :user_data_dir, :debugging_port
 
     def headless?
       @headless
diff --git a/lib/puppeteer/launcher/firefox.rb b/lib/puppeteer/launcher/firefox.rb
index 13a11a84..be45268c 100644
--- a/lib/puppeteer/launcher/firefox.rb
+++ b/lib/puppeteer/launcher/firefox.rb
@@ -28,7 +28,7 @@ def launch(options = {})
         end
 
       if firefox_arguments.none? { |arg| arg.start_with?('--remote-debugging-') }
-        firefox_arguments << '--remote-debugging-port=0'
+        firefox_arguments << "--remote-debugging-port=#{@chrome_arg_options.debugging_port}"
       end
 
       temporary_user_data_dir = nil
diff --git a/lib/puppeteer/puppeteer.rb b/lib/puppeteer/puppeteer.rb
index 9a2c1e80..67a0d766 100644
--- a/lib/puppeteer/puppeteer.rb
+++ b/lib/puppeteer/puppeteer.rb
@@ -44,6 +44,7 @@ def launch(
     args: nil,
     user_data_dir: nil,
     devtools: nil,
+    debugging_port: nil,
     headless: nil,
     ignore_https_errors: nil,
     default_viewport: NoViewport.new,
@@ -63,6 +64,7 @@ def launch(
       args: args,
       user_data_dir: user_data_dir,
       devtools: devtools,
+      debugging_port: debugging_port,
       headless: headless,
       ignore_https_errors: ignore_https_errors,
       default_viewport: default_viewport,
diff --git a/spec/integration/launcher_spec.rb b/spec/integration/launcher_spec.rb
index 377dd8f9..d134aaa4 100644
--- a/spec/integration/launcher_spec.rb
+++ b/spec/integration/launcher_spec.rb
@@ -260,6 +260,16 @@
         expect(screenshot.size).to be > 50000
       end
     end
+
+    it 'should set the debugging port' do
+      options = default_launch_options.merge(
+        debugging_port: 9999,
+      )
+
+      Puppeteer.launch(**options) do |browser|
+        expect(URI(browser.ws_endpoint).port).to eq(9999)
+      end
+    end
   end
 
   describe 'Puppeteer#default_args', puppeteer: :browser do