diff --git a/actionpack/lib/action_dispatch/http/filter_parameters.rb b/actionpack/lib/action_dispatch/http/filter_parameters.rb
index 2b851cc28d59ba17be3042721fbb62066af62382..3170389b36223a4b393f342d4804776392c901f8 100644
--- a/actionpack/lib/action_dispatch/http/filter_parameters.rb
+++ b/actionpack/lib/action_dispatch/http/filter_parameters.rb
@@ -16,7 +16,7 @@ module Http
     #   env["action_dispatch.parameter_filter"] = [:foo, "bar"]
     #   => replaces the value to all keys matching /foo|bar/i with "[FILTERED]"
     #
-    #   env["action_dispatch.parameter_filter"] = lambda do |k,v|
+    #   env["action_dispatch.parameter_filter"] = -> (k, v) do
     #     v.reverse! if k =~ /secret/i
     #   end
     #   => reverses the value to all keys matching /secret/i
diff --git a/actionpack/lib/action_dispatch/middleware/reloader.rb b/actionpack/lib/action_dispatch/middleware/reloader.rb
index 15b5a485359d48998d90bf4b5789116ee0f81676..6c7fba00cbe1a01b1516259ffad5b676132798e4 100644
--- a/actionpack/lib/action_dispatch/middleware/reloader.rb
+++ b/actionpack/lib/action_dispatch/middleware/reloader.rb
@@ -11,9 +11,9 @@ module ActionDispatch
   # the response body. This is important for streaming responses such as the
   # following:
   #
-  #     self.response_body = lambda { |response, output|
+  #     self.response_body = -> (response, output) do
   #       # code here which refers to application models
-  #     }
+  #     end
   #
   # Cleanup callbacks will not be called until after the response_body lambda
   # is evaluated, ensuring that it can refer to application models and other
diff --git a/actionpack/lib/action_dispatch/routing/mapper.rb b/actionpack/lib/action_dispatch/routing/mapper.rb
index 49009a45ccd73f44556467b8007dbe56155e53f5..0a444ddffcd528ca6fe5b9cefcab5f387e5309f4 100644
--- a/actionpack/lib/action_dispatch/routing/mapper.rb
+++ b/actionpack/lib/action_dispatch/routing/mapper.rb
@@ -418,7 +418,7 @@ def root(options = {})
         # A pattern can also point to a +Rack+ endpoint i.e. anything that
         # responds to +call+:
         #
-        #   match 'photos/:id', to: lambda {|hash| [200, {}, ["Coming soon"]] }, via: :get
+        #   match 'photos/:id', to: -> (hash) { [200, {}, ["Coming soon"]] }, via: :get
         #   match 'photos/:id', to: PhotoRackApp, via: :get
         #   # Yes, controller actions are just rack endpoints
         #   match 'photos/:id', to: PhotosController.action(:show), via: :get
@@ -470,7 +470,7 @@ def root(options = {})
         #   +call+ or a string representing a controller's action.
         #
         #      match 'path', to: 'controller#action', via: :get
-        #      match 'path', to: lambda { |env| [200, {}, ["Success!"]] }, via: :get
+        #      match 'path', to: -> (env) { [200, {}, ["Success!"]] }, via: :get
         #      match 'path', to: RackApp, via: :get
         #
         # [:on]
@@ -899,7 +899,7 @@ def namespace(path, options = {})
         #
         # Requests to routes can be constrained based on specific criteria:
         #
-        #    constraints(lambda { |req| req.env["HTTP_USER_AGENT"] =~ /iPhone/ }) do
+        #    constraints(-> (req) { req.env["HTTP_USER_AGENT"] =~ /iPhone/ }) do
         #      resources :iphones
         #    end
         #
diff --git a/actionview/lib/action_view/helpers/form_options_helper.rb b/actionview/lib/action_view/helpers/form_options_helper.rb
index 8a5928477fbe6d8891e8a3c2c2fcafd1b86d7de9..38fee3b314e281868e92e350d28d19913096546e 100644
--- a/actionview/lib/action_view/helpers/form_options_helper.rb
+++ b/actionview/lib/action_view/helpers/form_options_helper.rb
@@ -80,7 +80,7 @@ module Helpers
     #
     #   When used with the <tt>collection_select</tt> helper, <tt>:disabled</tt> can also be a Proc that identifies those options that should be disabled.
     #
-    #     collection_select(:post, :category_id, Category.all, :id, :name, {disabled: lambda{|category| category.archived? }})
+    #     collection_select(:post, :category_id, Category.all, :id, :name, {disabled: -> (category) { category.archived? }})
     #
     #   If the categories "2008 stuff" and "Christmas" return true when the method <tt>archived?</tt> is called, this would return:
     #     <select name="post[category_id]" id="post_category_id">