diff --git a/test/ruby/test_assignment.rb b/test/ruby/test_assignment.rb
index df0ae0713c..2b22613c55 100644
--- a/test/ruby/test_assignment.rb
+++ b/test/ruby/test_assignment.rb
@@ -490,7 +490,8 @@ class TestAssignment < Test::Unit::TestCase
   end
 end
 
-require 'sentence'
+require 'require_relative'
+require_relative 'sentence'
 class TestAssignmentGen < Test::Unit::TestCase
   Syntax = {
     :exp => [["0"],
diff --git a/test/ruby/test_marshal.rb b/test/ruby/test_marshal.rb
index a7f28c0f8b..ce9882b5e8 100644
--- a/test/ruby/test_marshal.rb
+++ b/test/ruby/test_marshal.rb
@@ -1,5 +1,6 @@
 require 'test/unit'
-require 'marshaltestlib'
+require 'require_relative'
+require_relative 'marshaltestlib'
 
 class TestMarshal < Test::Unit::TestCase
   include MarshalTestLib
diff --git a/test/ruby/test_yield.rb b/test/ruby/test_yield.rb
index ead0715d4e..e1169f5d51 100644
--- a/test/ruby/test_yield.rb
+++ b/test/ruby/test_yield.rb
@@ -74,7 +74,8 @@ class TestRubyYield < Test::Unit::TestCase
   end
 end
 
-require 'sentence'
+require 'require_relative'
+require_relative 'sentence'
 class TestRubyYieldGen < Test::Unit::TestCase
   Syntax = {
     :exp => [["0"],