diff --git a/tests/components/epson/test_config_flow.py b/tests/components/epson/test_config_flow.py
index 9c02feadc1a..088b1a5435c 100644
--- a/tests/components/epson/test_config_flow.py
+++ b/tests/components/epson/test_config_flow.py
@@ -21,6 +21,9 @@ async def test_form(hass):
     with patch(
         "homeassistant.components.epson.Projector.get_power",
         return_value="01",
+    ), patch(
+        "homeassistant.components.epson.Projector.get_serial_number",
+        return_value="12345",
     ), patch(
         "homeassistant.components.epson.async_setup_entry",
         return_value=True,