diff --git a/test/ruby/envutil.rb b/test/ruby/envutil.rb
index 3e0c1a3f00..3dafeab038 100644
--- a/test/ruby/envutil.rb
+++ b/test/ruby/envutil.rb
@@ -206,7 +206,7 @@ module Test
           'STDERR.puts('"#{token_dump}"'"START=#{$initial_size = Memory::Status.new.size}")',
           code,
         ].join("\n")
-        out, err, status = EnvUtil.invoke_ruby(args, cmd, true, true)
+        _, err, status = EnvUtil.invoke_ruby(args, cmd, true, true)
         before = err.sub!(/^#{token_re}START=(\d+)\n/, '') && $1.to_i
         after = err.sub!(/^#{token_re}FINAL=(\d+)\n/, '') && $1.to_i
         assert_equal([true, ""], [status.success?, err], message)
diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index d1a5514fad..11c1f6af67 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -245,7 +245,7 @@ class TestException < Test::Unit::TestCase
   end
 
   def test_thread_signal_location
-    stdout, stderr, status = EnvUtil.invoke_ruby("-d", <<-RUBY, false, true)
+    _, stderr, _ = EnvUtil.invoke_ruby("-d", <<-RUBY, false, true)
 Thread.start do
   begin
     Process.kill(:INT, $$)
@@ -400,7 +400,7 @@ end.join
       o = Object.new
       def o.exception(arg)
       end
-      RuntimeError.new("a") == o
+      _ = RuntimeError.new("a") == o
     EOC
     end
     assert_nothing_raised(ArgumentError, bug5865) do