diff --git a/activerecord/lib/active_record/railties/jdbcmysql_error.rb b/activerecord/lib/active_record/railties/jdbcmysql_error.rb
index 6b9af2a0cba84c20e03052b13b95efa6caa55d0d..0b7598348403138817500f7d5a696a9d733a1cd3 100644
--- a/activerecord/lib/active_record/railties/jdbcmysql_error.rb
+++ b/activerecord/lib/active_record/railties/jdbcmysql_error.rb
@@ -1,5 +1,5 @@
 #FIXME Remove if ArJdbcMysql will give.
-module ArJdbcMySQL
+module ArJdbcMySQL #:nodoc:
   class Error < StandardError
     attr_accessor :error_number, :sql_state
 
diff --git a/activesupport/lib/active_support/core_ext/hash/indifferent_access.rb b/activesupport/lib/active_support/core_ext/hash/indifferent_access.rb
index f4cb4454442daca062721720b9b0333eed876e86..7d54c9fae61d5be57b21d8a01216ae5d5dc64738 100644
--- a/activesupport/lib/active_support/core_ext/hash/indifferent_access.rb
+++ b/activesupport/lib/active_support/core_ext/hash/indifferent_access.rb
@@ -14,7 +14,7 @@ def with_indifferent_access
   # #with_indifferent_access. This method will be called on the current object
   # by the enclosing object and is aliased to #with_indifferent_access by
   # default. Subclasses of Hash may overwrite this method to return +self+ if
-  # converting to an +ActiveSupport::HashWithIndifferentAccess+ would not be
+  # converting to an <tt>ActiveSupport::HashWithIndifferentAccess</tt> would not be
   # desirable.
   #
   #   b = {:b => 1}
diff --git a/activesupport/lib/active_support/json/encoding.rb b/activesupport/lib/active_support/json/encoding.rb
index 0e1bf4c40b316f7857282d85bbf448490cbac48d..fcd83f8deae3d890458c059c995c5d77a05e76c6 100644
--- a/activesupport/lib/active_support/json/encoding.rb
+++ b/activesupport/lib/active_support/json/encoding.rb
@@ -148,8 +148,8 @@ def as_json(options = nil) #:nodoc:
   end
 end
 
-class Struct
-  def as_json(options = nil) #:nodoc:
+class Struct #:nodoc:
+  def as_json(options = nil)
     Hash[members.zip(values)]
   end
 end
diff --git a/railties/lib/rails/commands/benchmarker.rb b/railties/lib/rails/commands/benchmarker.rb
index 6c52d0f70fe70e85f3830ddafd0db0ed25ebcde5..b745b45e177196d129a753c2a069000723b59d08 100644
--- a/railties/lib/rails/commands/benchmarker.rb
+++ b/railties/lib/rails/commands/benchmarker.rb
@@ -21,7 +21,7 @@ def options
   options
 end
 
-class BenchmarkerTest < ActionDispatch::PerformanceTest
+class BenchmarkerTest < ActionDispatch::PerformanceTest #:nodoc:
   self.profile_options = options
 
   ARGV.each do |expression|
diff --git a/railties/lib/rails/commands/profiler.rb b/railties/lib/rails/commands/profiler.rb
index ea6347c9189f0bc57f44a6e54a575c2cd8c4e309..3f6966b4f09f10b937e3d22aa972d266bbe279d9 100644
--- a/railties/lib/rails/commands/profiler.rb
+++ b/railties/lib/rails/commands/profiler.rb
@@ -19,7 +19,7 @@ def options
   options
 end
 
-class ProfilerTest < ActionDispatch::PerformanceTest
+class ProfilerTest < ActionDispatch::PerformanceTest #:nodoc:
   self.profile_options = options
 
   ARGV.each do |expression|