diff --git a/lib/capybara.rb b/lib/capybara.rb
index 0da5706e..cd73eceb 100644
--- a/lib/capybara.rb
+++ b/lib/capybara.rb
@@ -5,6 +5,7 @@ require 'nokogiri'
 require 'xpath'
 require 'forwardable'
 require 'capybara/config'
+require 'capybara/registration_container'
 
 module Capybara
   class CapybaraError < StandardError; end
@@ -126,7 +127,7 @@ module Capybara
     # @yieldreturn [Capybara::Driver::Base]   A Capybara driver instance
     #
     def register_driver(name, &block)
-      drivers[name] = block
+      drivers.send(:register, name, block)
     end
 
     ##
@@ -145,7 +146,7 @@ module Capybara
     # @yieldparam host                        The host/ip to bind to
     #
     def register_server(name, &block)
-      servers[name.to_sym] = block
+      servers.send(:register, name.to_sym, block)
     end
 
     ##
@@ -199,11 +200,11 @@ module Capybara
     end
 
     def drivers
-      @drivers ||= {}
+      @drivers ||= RegistrationContainer.new
     end
 
     def servers
-      @servers ||= {}
+      @servers ||= RegistrationContainer.new
     end
 
     # Wraps the given string, which should contain an HTML document or fragment
diff --git a/lib/capybara/cucumber.rb b/lib/capybara/cucumber.rb
index fcfb073e..71cbadaa 100644
--- a/lib/capybara/cucumber.rb
+++ b/lib/capybara/cucumber.rb
@@ -22,6 +22,6 @@ end
 Before do |scenario|
   scenario.source_tag_names.each do |tag|
     driver_name = tag.sub(/^@/, '').to_sym
-    Capybara.current_driver = driver_name if Capybara.drivers.key?(driver_name)
+    Capybara.current_driver = driver_name if Capybara.drivers[driver_name]
   end
 end
diff --git a/lib/capybara/registration_container.rb b/lib/capybara/registration_container.rb
new file mode 100644
index 00000000..e1189408
--- /dev/null
+++ b/lib/capybara/registration_container.rb
@@ -0,0 +1,44 @@
+# frozen_string_literal: true
+
+module Capybara
+  # @api private
+  class RegistrationContainer
+    def names
+      @registered.keys
+    end
+
+    def [](name)
+      @registered[name]
+    end
+
+    def []=(name, value)
+      warn 'DEPRECATED: Directly setting drivers/servers is deprecated, please use Capybara.register_driver/register_server instead'
+      @registered[name] = value
+    end
+
+    def method_missing(method_name, *args, **options, &block)
+      if @registered.respond_to?(method_name)
+        warn "DEPRECATED: Calling '#{method_name}' on the drivers/servers container is deprecated without replacement"
+        # RUBY 2.6 will send an empty hash rather than nothing with **options so fix that
+        return @registered.public_send(method_name, *args, &block) if options.empty?
+
+        return @registered.public_send(method_name, *args, **options, &block)
+      end
+      super
+    end
+
+    def respond_to_missing?(method_name, include_private = false)
+      @registered.respond_to?(method_name) || super
+    end
+
+  private
+
+    def initialize
+      @registered = {}
+    end
+
+    def register(name, block)
+      @registered[name] = block
+    end
+  end
+end
diff --git a/lib/capybara/selenium/driver.rb b/lib/capybara/selenium/driver.rb
index 2cb10d3a..710f54c1 100644
--- a/lib/capybara/selenium/driver.rb
+++ b/lib/capybara/selenium/driver.rb
@@ -86,9 +86,7 @@ class Capybara::Selenium::Driver < Capybara::Driver::Base
   def html
     browser.page_source
   rescue Selenium::WebDriver::Error::JavascriptError => e
-    return '' if e.match?(/documentElement is null/)
-
-    raise
+    raise unless e.message.match?(/documentElement is null/)
   end
 
   def title
diff --git a/lib/capybara/session.rb b/lib/capybara/session.rb
index a66263ff..0691dc5c 100644
--- a/lib/capybara/session.rb
+++ b/lib/capybara/session.rb
@@ -97,8 +97,8 @@ module Capybara
 
     def driver
       @driver ||= begin
-        unless Capybara.drivers.key?(mode)
-          other_drivers = Capybara.drivers.keys.map(&:inspect)
+        unless Capybara.drivers[mode]
+          other_drivers = Capybara.drivers.names.map(&:inspect)
           raise Capybara::DriverNotFoundError, "no driver called #{mode.inspect} was found, available drivers: #{other_drivers.join(', ')}"
         end
         driver = Capybara.drivers[mode].call(app)
@@ -192,7 +192,7 @@ module Capybara
     # @return [String] A snapshot of the DOM of the current document, as it looks right now (potentially modified by JavaScript).
     #
     def html
-      driver.html
+      driver.html || ''
     end
     alias_method :body, :html
     alias_method :source, :html
diff --git a/spec/capybara_spec.rb b/spec/capybara_spec.rb
index e0f32dbe..8d53ae5e 100644
--- a/spec/capybara_spec.rb
+++ b/spec/capybara_spec.rb
@@ -32,7 +32,7 @@ RSpec.describe Capybara do
         # do nothing
       end
 
-      expect(described_class.servers).to have_key(:blob)
+      expect(described_class.servers[:blob]).to be_truthy
     end
   end