diff --git a/tests/minimalmodbus_test.py b/tests/minimalmodbus_test.py
index b504c4f..f2ee5ff 100755
--- a/tests/minimalmodbus_test.py
+++ b/tests/minimalmodbus_test.py
@@ -24,5 +24,11 @@ sleep(0.1)
 T_SCD4x = instrument.read_register(12, 1, functioncode=4)
 sleep(0.1)
 RH_SCD4x = instrument.read_register(13, 1, functioncode=4) * 10
+sleep(0.1)
+T_SHT4x_signed = instrument.read_register(14, 1, functioncode=4, signed=True)
+sleep(0.1)
+T_SCD4x_signed = instrument.read_register(15, 1, functioncode=4, signed=True)
 print(f'CO2:\t\t{CO2} ppm\nT_SHT4x:\t{T_SHT4x} deg C\nRH_SHT4x:\t{RH_SHT4x} %')
 print(f'T_SCD4x:\t{T_SCD4x} deg C\nRH_SCD4x:\t{RH_SCD4x} %')
+print(f'T_SHT4x_signed:\t{T_SHT4x_signed} deg C')
+print(f'T_SCD4x_signed:\t{T_SCD4x_signed} deg C')