diff --git a/tests/test_double_serializer.expected b/tests/test_double_serializer.expected
index 6678910..cd5f02b 100644
--- a/tests/test_double_serializer.expected
+++ b/tests/test_double_serializer.expected
@@ -9,3 +9,6 @@ obj.to_string(reset)=0.5
 obj.to_string(default format)=0.52381
 obj.to_string(with global format)=x0.524y
 obj.to_string(with thread format)=T0.52X
+obj.to_string(long thread format)=Ttttttttttttt0.52xxxxxxxxxxxxxxxxxxX
+obj.to_string(back to global format)=x0.524y
+obj.to_string(back to default format)=0.52381