diff --git a/ChangeLog b/ChangeLog
index e907134c49..79efcae520 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+Tue Aug 10 20:56:31 2010  Tanaka Akira  <akr@fsij.org>
+
+	* lib/optparse.rb: suppress a warning.
+
+	* test/test_mutex_m.rb: ditto.
+
 Tue Aug 10 20:56:13 2010  Tadayoshi Funaba  <tadf@dotrb.org>
 
 	* lib/date/format.rb (Date::Format::Bag): use Struct.
diff --git a/lib/optparse.rb b/lib/optparse.rb
index b07d91ef6c..4f631fbec6 100644
--- a/lib/optparse.rb
+++ b/lib/optparse.rb
@@ -1072,7 +1072,7 @@ class OptionParser
     default_style = Switch::NoArgument
     default_pattern = nil
     klass = nil
-    n, q, a = nil
+    q, a = nil
 
     opts.each do |o|
       # argument class
diff --git a/test/test_mutex_m.rb b/test/test_mutex_m.rb
index ab8927dd0f..a29f3f44b5 100644
--- a/test/test_mutex_m.rb
+++ b/test/test_mutex_m.rb
@@ -5,6 +5,7 @@ require 'mutex_m'
 class TestMutexM < Test::Unit::TestCase
   def test_cv_wait
     o = Object.new
+    o.instance_variable_set(:@foo, nil)
     o.extend(Mutex_m)
     c = ConditionVariable.new
     t = Thread.start {