diff --git a/homeassistant/components/derivative/sensor.py b/homeassistant/components/derivative/sensor.py
index a9c15dfe25e..73d297d7541 100644
--- a/homeassistant/components/derivative/sensor.py
+++ b/homeassistant/components/derivative/sensor.py
@@ -116,6 +116,10 @@ async def async_setup_entry(
     else:
         device_info = None
 
+    if (unit_prefix := config_entry.options.get(CONF_UNIT_PREFIX)) == "none":
+        # Before we had support for optional selectors, "none" was used for selecting nothing
+        unit_prefix = None
+
     derivative_sensor = DerivativeSensor(
         name=config_entry.title,
         round_digits=int(config_entry.options[CONF_ROUND_DIGITS]),
@@ -123,7 +127,7 @@ async def async_setup_entry(
         time_window=cv.time_period_dict(config_entry.options[CONF_TIME_WINDOW]),
         unique_id=config_entry.entry_id,
         unit_of_measurement=None,
-        unit_prefix=config_entry.options.get(CONF_UNIT_PREFIX),
+        unit_prefix=unit_prefix,
         unit_time=config_entry.options[CONF_UNIT_TIME],
         device_info=device_info,
     )
diff --git a/homeassistant/components/integration/sensor.py b/homeassistant/components/integration/sensor.py
index 909266c51d4..d7d5c84f17a 100644
--- a/homeassistant/components/integration/sensor.py
+++ b/homeassistant/components/integration/sensor.py
@@ -169,13 +169,17 @@ async def async_setup_entry(
     else:
         device_info = None
 
+    if (unit_prefix := config_entry.options.get(CONF_UNIT_PREFIX)) == "none":
+        # Before we had support for optional selectors, "none" was used for selecting nothing
+        unit_prefix = None
+
     integral = IntegrationSensor(
         integration_method=config_entry.options[CONF_METHOD],
         name=config_entry.title,
         round_digits=int(config_entry.options[CONF_ROUND_DIGITS]),
         source_entity=source_entity_id,
         unique_id=config_entry.entry_id,
-        unit_prefix=config_entry.options.get(CONF_UNIT_PREFIX),
+        unit_prefix=unit_prefix,
         unit_time=config_entry.options[CONF_UNIT_TIME],
         device_info=device_info,
     )
diff --git a/homeassistant/components/template/config_flow.py b/homeassistant/components/template/config_flow.py
index cd6b7c8937f..686c12fa4ba 100644
--- a/homeassistant/components/template/config_flow.py
+++ b/homeassistant/components/template/config_flow.py
@@ -176,8 +176,7 @@ def validate_user_input(
 ]:
     """Do post validation of user input.
 
-    For binary sensors: Strip none-sentinels.
-    For sensors: Strip none-sentinels and validate unit of measurement.
+    For sensors: Validate unit of measurement.
     For all domaines: Set template type.
     """