diff --git a/ChangeLog b/ChangeLog
index 36f54569ec..e681955315 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Tue Nov 11 23:43:51 2014  Tanaka Akira  <akr@fsij.org>
+
+	* test/fileutils/test_fileutils.rb: Use assert_join_threads.
+
 Tue Nov 11 22:51:14 2014  Tanaka Akira  <akr@fsij.org>
 
 	* test/resolv/test_dns.rb: Use assert_join_threads.
diff --git a/test/fileutils/test_fileutils.rb b/test/fileutils/test_fileutils.rb
index d948219959..5a9c1b1243 100644
--- a/test/fileutils/test_fileutils.rb
+++ b/test/fileutils/test_fileutils.rb
@@ -6,6 +6,7 @@ require_relative 'fileasserts'
 require 'pathname'
 require 'tmpdir'
 require 'test/unit'
+require_relative '../ruby/envutil'
 
 class TestFileUtils < Test::Unit::TestCase
   TMPROOT = "#{Dir.tmpdir}/fileutils.rb.#{$$}"
@@ -16,11 +17,12 @@ class TestFileUtils < Test::Unit::TestCase
     IO.pipe {|read, write|
       fu.instance_variable_set(:@fileutils_output, write)
       th = Thread.new { read.read }
-
-      yield
-
-      write.close
-      lines = th.value.lines.map {|l| l.chomp }
+      th2 = Thread.new {
+        yield
+        write.close
+      }
+      th_value, _ = assert_join_threads([th, th2])
+      lines = th_value.lines.map {|l| l.chomp }
       assert_equal(expected, lines)
     }
   ensure