diff --git a/actionpack/lib/action_dispatch/http/request.rb b/actionpack/lib/action_dispatch/http/request.rb
index 3c62c055e5..6985cec5f5 100644
--- a/actionpack/lib/action_dispatch/http/request.rb
+++ b/actionpack/lib/action_dispatch/http/request.rb
@@ -290,7 +290,7 @@ module ActionDispatch
 
     # Override Rack's GET method to support indifferent access
     def GET
-      @env["action_dispatch.request.query_parameters"] ||= Utils.deep_munge(normalize_encode_params(super || {}))
+      @env["action_dispatch.request.query_parameters"] ||= normalize_encode_params(super || {})
     rescue Rack::Utils::ParameterTypeError, Rack::Utils::InvalidParameterError => e
       raise ActionController::BadRequest.new(:query, e)
     end
@@ -298,7 +298,7 @@ module ActionDispatch
 
     # Override Rack's POST method to support indifferent access
     def POST
-      @env["action_dispatch.request.request_parameters"] ||= Utils.deep_munge(normalize_encode_params(super || {}))
+      @env["action_dispatch.request.request_parameters"] ||= normalize_encode_params(super || {})
     rescue Rack::Utils::ParameterTypeError, Rack::Utils::InvalidParameterError => e
       raise ActionController::BadRequest.new(:request, e)
     end
@@ -318,11 +318,6 @@ module ActionDispatch
       LOCALHOST =~ remote_addr && LOCALHOST =~ remote_ip
     end
 
-    protected
-      def parse_query(*)
-        Utils.deep_munge(super)
-      end
-
     private
       def check_method(name)
         HTTP_METHOD_LOOKUP[name] || raise(ActionController::UnknownHttpMethod, "#{name}, accepted HTTP methods are #{HTTP_METHODS[0...-1].join(', ')}, and #{HTTP_METHODS[-1]}")
diff --git a/actionpack/lib/action_dispatch/middleware/params_parser.rb b/actionpack/lib/action_dispatch/middleware/params_parser.rb
index e2b3b06fd8..2617956c74 100644
--- a/actionpack/lib/action_dispatch/middleware/params_parser.rb
+++ b/actionpack/lib/action_dispatch/middleware/params_parser.rb
@@ -17,7 +17,7 @@ module ActionDispatch
       Mime::JSON => lambda { |raw_post|
         data = ActiveSupport::JSON.decode(raw_post)
         data = {:_json => data} unless data.is_a?(Hash)
-        Request::Utils.deep_munge(data).with_indifferent_access
+        Request::Utils.normalize_encode_params(data)
       }
     }
 
diff --git a/actionpack/lib/action_dispatch/request/utils.rb b/actionpack/lib/action_dispatch/request/utils.rb
index 01fd5efd5e..3973ea6346 100644
--- a/actionpack/lib/action_dispatch/request/utils.rb
+++ b/actionpack/lib/action_dispatch/request/utils.rb
@@ -6,10 +6,14 @@ module ActionDispatch
       self.perform_deep_munge = true
 
       def self.normalize_encode_params(params)
-        ParamEncoder.normalize_encode_params params
+        if perform_deep_munge
+          NoNilParamEncoder.normalize_encode_params params
+        else
+          ParamEncoder.normalize_encode_params params
+        end
       end
 
-      class ParamEncoder
+      class ParamEncoder # :nodoc:
         # Convert nested Hash to HashWithIndifferentAccess.
         #
         def self.normalize_encode_params(params)
@@ -34,22 +38,12 @@ module ActionDispatch
         end
       end
 
-      class << self
-        # Remove nils from the params hash
-        def deep_munge(hash)
-          return hash unless perform_deep_munge
-
-          hash.each do |k, v|
-            case v
-            when Array
-              v.grep(Hash) { |x| deep_munge(x) }
-              v.compact!
-            when Hash
-              deep_munge(v)
-            end
-          end
-
-          hash
+      # Remove nils from the params hash
+      class NoNilParamEncoder < ParamEncoder # :nodoc:
+        def self.handle_array(params)
+          list = super
+          list.compact!
+          list
         end
       end
     end