diff --git a/lib/mongoid/association/relatable.rb b/lib/mongoid/association/relatable.rb
index fc485c4d94..ca201314b7 100644
--- a/lib/mongoid/association/relatable.rb
+++ b/lib/mongoid/association/relatable.rb
@@ -303,7 +303,7 @@ def validate?
       # The associations above this one in the inclusion tree.
       #
       # @return [ Array<String> ] The associations.
-      attr_accessor :parent_inclusions
+      attr_writer :parent_inclusions
 
       # The associations above this one in the inclusion tree.
       #
diff --git a/lib/mongoid/contextual.rb b/lib/mongoid/contextual.rb
index fe0024be7e..b34aac87cd 100644
--- a/lib/mongoid/contextual.rb
+++ b/lib/mongoid/contextual.rb
@@ -23,7 +23,7 @@ module Contextual
 
     # The methods in the contexts themselves should all get delegated to,
     # including destructive, modification, and optional methods.
-    def_delegators :context, *(Mongo.public_instance_methods(false) - [ :skip, :limit ])
+    def_delegators :context, *(Mongo.public_instance_methods(false) - [ :skip, :limit, :load_async ])
 
     # This gets blank and empty included.
     def_delegators :context, *Queryable.public_instance_methods(false)
diff --git a/lib/mongoid/findable.rb b/lib/mongoid/findable.rb
index 93a12ce169..891c66077c 100644
--- a/lib/mongoid/findable.rb
+++ b/lib/mongoid/findable.rb
@@ -56,13 +56,12 @@ module Findable
       :take,
       :take!,
       :tally,
-      :text_search,
       :third,
       :third!,
       :third_to_last,
       :third_to_last!,
       :update,
-      :update_all,
+      :update_all
 
     # Returns a count of records in the database.
     # If you want to specify conditions use where.
diff --git a/lib/mongoid/serializable.rb b/lib/mongoid/serializable.rb
index d1c115b7ca..1f8cb81422 100644
--- a/lib/mongoid/serializable.rb
+++ b/lib/mongoid/serializable.rb
@@ -13,6 +13,9 @@ module Serializable
     included do
 
       class << self
+        # These methods are previously defined by ActiveModel which we override to include default behavior.
+        remove_method :include_root_in_json if method_defined?(:include_root_in_json)
+        remove_method :include_root_in_json= if method_defined?(:include_root_in_json=)
         def include_root_in_json
           @include_root_in_json.nil? ? ::Mongoid.include_root_in_json : @include_root_in_json
         end
diff --git a/lib/mongoid/traversable.rb b/lib/mongoid/traversable.rb
index 7fb26d5930..349305640e 100644
--- a/lib/mongoid/traversable.rb
+++ b/lib/mongoid/traversable.rb
@@ -179,8 +179,9 @@ def discriminator_value
 
     included do
       class_attribute :discriminator_key, instance_accessor: false
-
       class << self
+        # The class attribute declaration above creates a default getter which we override with our custom method.
+        remove_method :discriminator_key
         delegate :discriminator_key, to: ::Mongoid
         prepend DiscriminatorAssignment
         include DiscriminatorRetrieval