diff --git a/homeassistant/components/p1_monitor/config_flow.py b/homeassistant/components/p1_monitor/config_flow.py
index 055973e8e37..a7ede186d72 100644
--- a/homeassistant/components/p1_monitor/config_flow.py
+++ b/homeassistant/components/p1_monitor/config_flow.py
@@ -57,10 +57,13 @@ class P1MonitorFlowHandler(ConfigFlow, domain=DOMAIN):
             data_schema=vol.Schema(
                 {
                     vol.Required(CONF_HOST): TextSelector(),
-                    vol.Required(CONF_PORT, default=80): NumberSelector(
-                        NumberSelectorConfig(
-                            mode=NumberSelectorMode.BOX,
-                        )
+                    vol.Required(CONF_PORT, default=80): vol.All(
+                        NumberSelector(
+                            NumberSelectorConfig(
+                                min=1, max=65535, mode=NumberSelectorMode.BOX
+                            ),
+                        ),
+                        vol.Coerce(int),
                     ),
                 }
             ),
diff --git a/tests/components/p1_monitor/test_config_flow.py b/tests/components/p1_monitor/test_config_flow.py
index ea1d12055a0..cbd89320074 100644
--- a/tests/components/p1_monitor/test_config_flow.py
+++ b/tests/components/p1_monitor/test_config_flow.py
@@ -36,6 +36,7 @@ async def test_full_user_flow(hass: HomeAssistant) -> None:
     assert result2.get("type") is FlowResultType.CREATE_ENTRY
     assert result2.get("title") == "P1 Monitor"
     assert result2.get("data") == {CONF_HOST: "example.com", CONF_PORT: 80}
+    assert isinstance(result2["data"][CONF_PORT], int)
 
     assert len(mock_setup_entry.mock_calls) == 1
     assert len(mock_p1monitor.mock_calls) == 1