diff --git a/lib/rackstash/filters/replace.rb b/lib/rackstash/filters/replace.rb
index f574cba..40ec694 100644
--- a/lib/rackstash/filters/replace.rb
+++ b/lib/rackstash/filters/replace.rb
@@ -8,10 +8,13 @@
 module Rackstash
   module Filters
     # Replace fields in the given event with new values. A new value can be
-    # specified as either a fixed value or as a Proc (or any other object
+    # specified as either a fixed value or as a `Proc` (or any other object
     # responding to `call`). In the latter case, the callable object will be
-    # called with the event as its argument. It is then expectd to return the
-    # new value which is set on the key
+    # called with the event as its argument. It is then expected to return the
+    # new value which is set on the key.
+    #
+    # If a specified field does not exist in the event hash, it will be created
+    # with the given (or calculated) value anyway.
     #
     # @example
     #   Rackstash::Flow.new(STDOUT) do
@@ -20,8 +23,9 @@ module Rackstash
     #     }
     #   end
     #
-    # You should make sure to only set a new object of the basic types here,
-    # namely `String`, `Integer`, `Float`, `nil`, `true`, or `false`.
+    # You should make sure to only set a new object of one of the basic types
+    # here, namely `String`, `Integer`, `Float`, `Hash`, `Array`, `nil`, `true`,
+    # or `false`.
     class Replace
       # @param spec [Hash<#to_s => #call,Object>] a `Hash` specifying new field
       #   values for the named keys. Values can be given in the form of a fixed
@@ -34,9 +38,7 @@ module Rackstash
         end
       end
 
-      # Replace field values in the event to a new value. If a specified field
-      # does not exist in the event hah, it will be created with the goven (or
-      # calculated) value anyway.
+      # Replace or set fields in the event to a new value.
       #
       # @param event [Hash] an event hash
       # return [Hash] the given `event` with the fields renamed