diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index c7bab3a8d..9463e56ca 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -9,6 +9,7 @@ title: Changelog
 
 ## main
 
+* Include polymorphic slots in `ViewComponent::Base` by default.
 * Add per-component config option for stripping newlines from templates before compilation.
 
     *Cameron Dutro*
diff --git a/docs/guide/slots.md b/docs/guide/slots.md
index 4be4df62a..ad2f3c4c5 100644
--- a/docs/guide/slots.md
+++ b/docs/guide/slots.md
@@ -233,16 +233,14 @@ Slot content can also be set using `#with_content`:
 
 _To view documentation for content_areas (deprecated) and the original implementation of Slots (deprecated), see [/content_areas](/content_areas) and [/slots_v1](/slots_v1)._
 
-## Polymorphic slots (Experimental)
+## Polymorphic slots
 
-Polymorphic slots can render one of several possible slots. To use this experimental feature, include `ViewComponent::PolymorphicSlots`.
+Polymorphic slots can render one of several possible slots.
 
 For example, consider this list item component that can be rendered with either an icon or an avatar visual. The `visual` slot is passed a hash mapping types to slot definitions:
 
 ```ruby
 class ListItemComponent < ViewComponent::Base
-  include ViewComponent::PolymorphicSlots
-
   renders_one :visual, types: {
     icon: IconComponent,
     avatar: lambda { |**system_arguments|
diff --git a/lib/view_component/base.rb b/lib/view_component/base.rb
index eca04b5bd..136e1a455 100644
--- a/lib/view_component/base.rb
+++ b/lib/view_component/base.rb
@@ -16,6 +16,7 @@ module ViewComponent
   class Base < ActionView::Base
     include ActiveSupport::Configurable
     include ViewComponent::ContentAreas
+    include ViewComponent::PolymorphicSlots
     include ViewComponent::Previewable
     include ViewComponent::SlotableV2
     include ViewComponent::Translatable
diff --git a/lib/view_component/polymorphic_slots.rb b/lib/view_component/polymorphic_slots.rb
index 8bdba5b6a..867c44193 100644
--- a/lib/view_component/polymorphic_slots.rb
+++ b/lib/view_component/polymorphic_slots.rb
@@ -5,6 +5,17 @@ module PolymorphicSlots
     # In older rails versions, using a concern isn't a good idea here because they appear to not work with
     # Module#prepend and class methods.
     def self.included(base)
+      if base != ViewComponent::Base
+        # :nocov:
+        location = Kernel.caller_locations(1, 1)[0]
+
+        warn(
+          "warning: ViewComponent::PolymorphicSlots is now included in ViewComponent::Base by default "\
+          "and can be removed from #{location.path}:#{location.lineno}"
+        )
+        # :nocov:
+      end
+
       base.singleton_class.prepend(ClassMethods)
       base.include(InstanceMethods)
     end
@@ -45,8 +56,12 @@ def register_polymorphic_slot(slot_name, types, collection:)
               "#{slot_name}_#{poly_type}"
             end
 
-          # Deprecated: Will be removed in 3.0
           define_method(setter_name) do |*args, &block|
+            ViewComponent::Deprecation.warn(
+              "polymorphic slot setters like `#{setter_name}` are deprecated and will be removed in"\
+              "ViewComponent v3.0.0.\n\nUse `with_#{setter_name}` instead."
+            )
+
             set_polymorphic_slot(slot_name, poly_type, *args, &block)
           end
           ruby2_keywords(setter_name.to_sym) if respond_to?(:ruby2_keywords, true)
diff --git a/test/sandbox/app/components/polymorphic_slot_component.rb b/test/sandbox/app/components/polymorphic_slot_component.rb
index 3324bfd72..b4ced91c7 100644
--- a/test/sandbox/app/components/polymorphic_slot_component.rb
+++ b/test/sandbox/app/components/polymorphic_slot_component.rb
@@ -1,8 +1,6 @@
 # frozen_string_literal: true
 
 class PolymorphicSlotComponent < ViewComponent::Base
-  include ViewComponent::PolymorphicSlots
-
   renders_one :header, types: {
     standard: lambda { |&block| content_tag(:div, class: "standard", &block) },
     special: lambda { |&block| content_tag(:div, class: "special", &block) }