diff --git a/lib/capybara/queries/selector_query.rb b/lib/capybara/queries/selector_query.rb
index 6f5978a3..a308aa0f 100644
--- a/lib/capybara/queries/selector_query.rb
+++ b/lib/capybara/queries/selector_query.rb
@@ -240,10 +240,15 @@ module Capybara
       end
 
       def filtered_css(expr)
+        id_conditions = conditions_from_id if use_default_id_filter?
+        id_conditions = [''] unless id_conditions&.any?
+
+        class_conditions = conditions_from_classes if use_default_class_filter?
+        class_conditions = [''] unless class_conditions&.any?
+
+        conditions = id_conditions.product(class_conditions)
         ::Capybara::Selector::CSS.split(expr).map do |sel|
-          sel += conditions_from_id if use_default_id_filter?
-          sel += conditions_from_classes if use_default_class_filter?
-          sel
+          conditions.map { |(id_cond, class_cond)| sel + id_cond + class_cond }.join(', ')
         end.join(', ')
       end
 
@@ -260,7 +265,7 @@ module Capybara
       end
 
       def conditions_from_id
-        builder.attribute_conditions(id: options[:id])
+        builder.id_conditions(options[:id])
       end
 
       def apply_expression_filters(expression)
diff --git a/lib/capybara/selector.rb b/lib/capybara/selector.rb
index 713959bd..0b4ae611 100644
--- a/lib/capybara/selector.rb
+++ b/lib/capybara/selector.rb
@@ -34,7 +34,7 @@ Capybara.add_selector(:css) do
 end
 
 Capybara.add_selector(:id) do
-  xpath { |id| XPath.descendant[builder.attribute_conditions(id: id)] }
+  xpath { |id| XPath.descendant[builder.id_conditions(id)] }
   locator_filter {  |node, id| id.is_a?(Regexp) ? node[:id] =~ id : true }
 end
 
diff --git a/lib/capybara/selector/builders/css_builder.rb b/lib/capybara/selector/builders/css_builder.rb
index 9d612992..06d65f10 100644
--- a/lib/capybara/selector/builders/css_builder.rb
+++ b/lib/capybara/selector/builders/css_builder.rb
@@ -35,11 +35,28 @@ module Capybara
           when XPath::Expression
             raise ArgumentError, 'XPath expressions are not supported for the :class filter with CSS based selectors'
           when Regexp
-            attribute_conditions(class: classes)
+            Selector::RegexpDisassembler.new(classes).alternated_substrings.map do |strs|
+              strs.map do |str|
+                "[class*='#{str}'#{' i' if classes.casefold?}]"
+              end.join
+            end
           else
             cls = Array(classes).group_by { |cl| cl.start_with?('!') && !cl.start_with?('!!!') }
-            (cls[false].to_a.map { |cl| ".#{Capybara::Selector::CSS.escape(cl.sub(/^!!/, ''))}" } +
-            cls[true].to_a.map { |cl| ":not(.#{Capybara::Selector::CSS.escape(cl.slice(1..-1))})" }).join
+            [(cls[false].to_a.map { |cl| ".#{Capybara::Selector::CSS.escape(cl.sub(/^!!/, ''))}" } +
+            cls[true].to_a.map { |cl| ":not(.#{Capybara::Selector::CSS.escape(cl.slice(1..-1))})" }).join]
+          end
+        end
+
+        def id_conditions(id)
+          case id
+          when Regexp
+            Selector::RegexpDisassembler.new(id).alternated_substrings.map do |id_strs|
+              id_strs.map do |str|
+                "[id*='#{str}'#{' i' if id.casefold?}]"
+              end.join
+            end
+          else
+            [attribute_conditions(id: id)]
           end
         end
       end
diff --git a/lib/capybara/selector/builders/xpath_builder.rb b/lib/capybara/selector/builders/xpath_builder.rb
index 60a6acb5..bf10e3a3 100644
--- a/lib/capybara/selector/builders/xpath_builder.rb
+++ b/lib/capybara/selector/builders/xpath_builder.rb
@@ -39,6 +39,10 @@ module Capybara
           end
         end
 
+        def id_conditions(id)
+          attribute_conditions(id: id)
+        end
+
       private
 
         def regexp_to_xpath_conditions(regexp)
diff --git a/lib/capybara/spec/session/has_css_spec.rb b/lib/capybara/spec/session/has_css_spec.rb
index 70eea0f6..b0a6b38a 100644
--- a/lib/capybara/spec/session/has_css_spec.rb
+++ b/lib/capybara/spec/session/has_css_spec.rb
@@ -27,11 +27,15 @@ Capybara::SpecHelper.spec '#has_css?' do
     expect(@session).to have_css('h2', id: 'h2one')
     expect(@session).to have_css('h2')
     expect(@session).to have_css('h2', id: /h2o/)
+    expect(@session).to have_css('li', id: /john|paul/)
   end
 
   it 'should support :class option' do
     expect(@session).to have_css('li', class: 'guitarist')
     expect(@session).to have_css('li', class: /guitar/)
+    expect(@session).to have_css('li', class: /guitar|drummer/)
+    expect(@session).to have_css('li', class: %w[beatle guitarist])
+    expect(@session).to have_css('li', class: /.*/)
   end
 
   it 'should support case insensitive :class and :id options' do
@@ -111,6 +115,9 @@ Capybara::SpecHelper.spec '#has_css?' do
       expect(@session).to have_css('p', count: 3)
       expect(@session).to have_css('p a#foo', count: 1)
       expect(@session).to have_css('p a.doesnotexist', count: 0)
+      expect(@session).to have_css('li', class: /guitar|drummer/, count: 4)
+      expect(@session).to have_css('li', id: /john|paul/, class: /guitar|drummer/, count: 2)
+      expect(@session).to have_css('li', class: %w[beatle guitarist], count: 2)
     end
 
     it 'should be false if the content occurs a different number of times than the given' do
diff --git a/lib/capybara/spec/session/has_xpath_spec.rb b/lib/capybara/spec/session/has_xpath_spec.rb
index 16d9afa5..3332e175 100644
--- a/lib/capybara/spec/session/has_xpath_spec.rb
+++ b/lib/capybara/spec/session/has_xpath_spec.rb
@@ -11,6 +11,20 @@ Capybara::SpecHelper.spec '#has_xpath?' do
     expect(@session).to have_xpath("//p[contains(.,'est')]")
   end
 
+  it 'should support :id option' do
+    expect(@session).to have_xpath('//h2', id: 'h2one')
+    expect(@session).to have_xpath('//h2')
+    expect(@session).to have_xpath('//h2', id: /h2o/)
+  end
+
+  it 'should support :class option' do
+    expect(@session).to have_xpath('//li', class: 'guitarist')
+    expect(@session).to have_xpath('//li', class: /guitar/)
+    expect(@session).to have_xpath('//li', class: /guitar|drummer/)
+    expect(@session).to have_xpath('//li', class: %w[beatle guitarist])
+    expect(@session).to have_xpath('//li', class: /.*/)
+  end
+
   it 'should be false if the given selector is not on the page' do
     expect(@session).not_to have_xpath('//abbr')
     expect(@session).not_to have_xpath("//p//a[@id='doesnotexist']")
@@ -43,6 +57,9 @@ Capybara::SpecHelper.spec '#has_xpath?' do
       expect(@session).to have_xpath("//p//a[@id='foo']", count: 1)
       expect(@session).to have_xpath("//p[contains(.,'est')]", count: 1)
       expect(@session).to have_xpath("//p//a[@id='doesnotexist']", count: 0)
+      expect(@session).to have_xpath('//li', class: /guitar|drummer/, count: 4)
+      expect(@session).to have_xpath('//li', id: /john|paul/, class: /guitar|drummer/, count: 2)
+      expect(@session).to have_xpath('//li', class: %w[beatle guitarist], count: 2)
     end
 
     it 'should be false if the content occurs a different number of times than the given' do