diff --git a/source/workbook/tests/test_read.hpp b/source/workbook/tests/test_read.hpp
index 12dcbc87..2aa2a8ae 100644
--- a/source/workbook/tests/test_read.hpp
+++ b/source/workbook/tests/test_read.hpp
@@ -523,9 +523,8 @@ public:
         pugi::xml_document xml;
         xml.load(source.c_str());
 
-        xlnt::shared_strings_serializer serializer;
         std::vector<xlnt::text> strings;
-        serializer.read_shared_strings(xml, strings);
+        xlnt::shared_strings_serializer::read_shared_strings(xml, strings);
 
         TS_ASSERT_EQUALS(strings.size(), 1);
         TS_ASSERT_EQUALS(strings.front().get_runs().size(), 1);
@@ -553,6 +552,6 @@ public:
         pugi::xml_document xml_bad;
         xml_bad.load(source_bad.c_str());
 
-        TS_ASSERT_THROWS(serializer.read_shared_strings(xml_bad, strings), std::runtime_error);
+        TS_ASSERT_THROWS(xlnt::shared_strings_serializer::read_shared_strings(xml_bad, strings), std::runtime_error);
     }
 };
diff --git a/source/workbook/tests/test_write_workbook.hpp b/source/workbook/tests/test_write_workbook.hpp
index 53aa0203..e2195e2a 100644
--- a/source/workbook/tests/test_write_workbook.hpp
+++ b/source/workbook/tests/test_write_workbook.hpp
@@ -201,9 +201,9 @@ public:
         xlnt::text text;
         text.add_run(run);
         cell.set_value(text);
-        xlnt::shared_strings_serializer serializer;
+
         pugi::xml_document xml;
-        serializer.write_shared_strings(wb.get_shared_strings(), xml);
+        xlnt::shared_strings_serializer::write_shared_strings(wb.get_shared_strings(), xml);
 
         std::string expected =
         "<sst xmlns=\"http://schemas.openxmlformats.org/spreadsheetml/2006/main\" count=\"1\" uniqueCount=\"1\">"