diff --git a/test/drb/drbtest.rb b/test/drb/drbtest.rb
index ed952b5751..efbdb5b5a6 100644
--- a/test/drb/drbtest.rb
+++ b/test/drb/drbtest.rb
@@ -127,7 +127,7 @@ module DRbCore
       @there.sum(1, 1, 1, 1, 1, 1, 1, 1, 1)
     end
     assert_raises(DRb::DRbConnError) do
-      @there.sum('1' * 2048)
+      @there.sum('1' * 4096)
     end
   end
 
@@ -215,8 +215,15 @@ module DRbCore
     assert_equal(DRb::DRbURIOption.new('?hello?world'), ro.__drbref)
   end
 
+  def test_10_yield
+    @there.simple_hash.each do |k, v|
+      assert_kind_of(String, k)
+      assert_kind_of(Symbol, v)
+    end
+  end
+
   def test_10_yield_undumped
-    @there.xarray2_hash.each_pair do |k, v|
+    @there.xarray2_hash.each do |k, v|
       assert_kind_of(String, k)
       assert_kind_of(DRbObject, v)
     end
diff --git a/test/drb/ut_drb.rb b/test/drb/ut_drb.rb
index 2a121b0de3..2525aa681a 100644
--- a/test/drb/ut_drb.rb
+++ b/test/drb/ut_drb.rb
@@ -107,6 +107,13 @@ class DRbEx
     DRbObject.new(@xary2_hash)
   end
 
+  def simple_hash
+    unless @hash
+      @hash = { 'a'=>:a, 'b'=>:b }
+    end
+    DRbObject.new(@hash)
+  end
+
   def [](key)
     key.to_s
   end
@@ -129,7 +136,7 @@ if __FILE__ == $0
   end
 
   DRb::DRbServer.default_argc_limit(8)
-  DRb::DRbServer.default_load_limit(2048)
+  DRb::DRbServer.default_load_limit(4096)
   DRb.start_service(nil, DRbEx.new)
   es = DRb::ExtServ.new(ARGV.shift, ARGV.shift)
   DRb.thread.join
diff --git a/test/drb/ut_drb_drbssl.rb b/test/drb/ut_drb_drbssl.rb
index b09864aebe..cd9adf9716 100644
--- a/test/drb/ut_drb_drbssl.rb
+++ b/test/drb/ut_drb_drbssl.rb
@@ -17,7 +17,7 @@ if __FILE__ == $0
     [ ["C","JP"], ["O","Foo.DRuby.Org"], ["CN", "Sample"] ]
 
   DRb::DRbServer.default_argc_limit(8)
-  DRb::DRbServer.default_load_limit(1024)
+  DRb::DRbServer.default_load_limit(4096)
   DRb.start_service('drbssl://:0', DRbEx.new, config)
   es = DRb::ExtServ.new(ARGV.shift, ARGV.shift)
   DRb.thread.join
diff --git a/test/drb/ut_drb_drbunix.rb b/test/drb/ut_drb_drbunix.rb
index ae0674ef37..8b9484cf9c 100644
--- a/test/drb/ut_drb_drbunix.rb
+++ b/test/drb/ut_drb_drbunix.rb
@@ -8,7 +8,7 @@ if __FILE__ == $0
   end
 
   DRb::DRbServer.default_argc_limit(8)
-  DRb::DRbServer.default_load_limit(1024)
+  DRb::DRbServer.default_load_limit(4096)
   DRb.start_service('drbunix:', DRbEx.new)
   es = DRb::ExtServ.new(ARGV.shift, ARGV.shift)
   DRb.thread.join