diff --git a/tool/lib/test/unit.rb b/tool/lib/test/unit.rb
index fd3b19406c..3067809153 100644
--- a/tool/lib/test/unit.rb
+++ b/tool/lib/test/unit.rb
@@ -574,9 +574,9 @@ module Test
           jobs_status(worker)
         when /^done (.+?)$/
           begin
-            r = Marshal.load($1.unpack("m")[0])
+            r = Marshal.load($1.unpack1("m"))
           rescue
-            print "unknown object: #{$1.unpack("m")[0].dump}"
+            print "unknown object: #{$1.unpack1("m").dump}"
             return true
           end
           result << r[0..1] unless r[0..1] == [nil,nil]
@@ -587,7 +587,7 @@ module Test
           return true
         when /^record (.+?)$/
           begin
-            r = Marshal.load($1.unpack("m")[0])
+            r = Marshal.load($1.unpack1("m"))
 
             suite = r.first
             key = [worker.name, suite]
@@ -597,18 +597,18 @@ module Test
               @records[key] = [worker.start_time, Time.now]
             end
           rescue => e
-            print "unknown record: #{e.message} #{$1.unpack("m")[0].dump}"
+            print "unknown record: #{e.message} #{$1.unpack1("m").dump}"
             return true
           end
           record(fake_class(r[0]), *r[1..-1])
         when /^p (.+?)$/
           del_jobs_status
-          print $1.unpack("m")[0]
+          print $1.unpack1("m")
           jobs_status(worker) if @options[:job_status] == :replace
         when /^after (.+?)$/
-          @warnings << Marshal.load($1.unpack("m")[0])
+          @warnings << Marshal.load($1.unpack1("m"))
         when /^bye (.+?)$/
-          after_worker_down worker, Marshal.load($1.unpack("m")[0])
+          after_worker_down worker, Marshal.load($1.unpack1("m"))
         when /^bye$/, nil
           if shutting_down || worker.quit_called
             after_worker_quit worker
diff --git a/tool/lib/test/unit/parallel.rb b/tool/lib/test/unit/parallel.rb
index 96aadf0249..db2d918331 100644
--- a/tool/lib/test/unit/parallel.rb
+++ b/tool/lib/test/unit/parallel.rb
@@ -107,7 +107,7 @@ module Test
             case buf.chomp
             when /^loadpath (.+?)$/
               @old_loadpath = $:.dup
-              $:.push(*Marshal.load($1.unpack("m")[0].force_encoding("ASCII-8BIT"))).uniq!
+              $:.push(*Marshal.load($1.unpack1("m").force_encoding("ASCII-8BIT"))).uniq!
             when /^run (.+?) (.+?)$/
               _report "okay"
 
diff --git a/tool/test/testunit/test_parallel.rb b/tool/test/testunit/test_parallel.rb
index 297ff414ed..8207e71868 100644
--- a/tool/test/testunit/test_parallel.rb
+++ b/tool/test/testunit/test_parallel.rb
@@ -99,7 +99,7 @@ module TestParallel
           break if /^p (.+?)$/ =~ buf
         end
         assert_not_nil($1, "'p' was not found")
-        assert_match(/TestA#test_nothing_test = \d+\.\d+ s = \.\n/, $1.chomp.unpack("m")[0])
+        assert_match(/TestA#test_nothing_test = \d+\.\d+ s = \.\n/, $1.chomp.unpack1("m"))
       end
     end
 
@@ -111,7 +111,7 @@ module TestParallel
         end
         assert_not_nil($1, "'done' was not found")
 
-        result = Marshal.load($1.chomp.unpack("m")[0])
+        result = Marshal.load($1.chomp.unpack1("m"))
         assert_equal(5, result[0])
         pend "TODO: result[1] returns 17. We should investigate it" do
           assert_equal(12, result[1])