diff --git a/test/json/json_common_interface_test.rb b/test/json/json_common_interface_test.rb
index 4fb161569..0fbc2df7a 100644
--- a/test/json/json_common_interface_test.rb
+++ b/test/json/json_common_interface_test.rb
@@ -129,6 +129,7 @@ def test_load
     tempfile.write @json
     tempfile.rewind
     assert_equal @hash, JSON.load(tempfile)
+    tempfile.close!
 
     stringio = StringIO.new(@json)
     stringio.rewind