diff --git a/homeassistant/components/template/template_entity.py b/homeassistant/components/template/template_entity.py
index 3e70e1c3546fc..f5b84b1ad7ad8 100644
--- a/homeassistant/components/template/template_entity.py
+++ b/homeassistant/components/template/template_entity.py
@@ -535,13 +535,15 @@ def _async_setup_templates(self) -> None:
             )
         if self._entity_picture_template is not None:
             self.add_template_attribute(
-                "_attr_entity_picture", self._entity_picture_template
+                "_attr_entity_picture", self._entity_picture_template, cv.string
             )
         if (
             self._friendly_name_template is not None
             and not self._friendly_name_template.is_static
         ):
-            self.add_template_attribute("_attr_name", self._friendly_name_template)
+            self.add_template_attribute(
+                "_attr_name", self._friendly_name_template, cv.string
+            )
 
     @callback
     def async_start_preview(
diff --git a/tests/components/template/test_sensor.py b/tests/components/template/test_sensor.py
index 5a7521f98c737..929a890ab384f 100644
--- a/tests/components/template/test_sensor.py
+++ b/tests/components/template/test_sensor.py
@@ -12,6 +12,7 @@
 from homeassistant.components.template.sensor import TriggerSensorEntity
 from homeassistant.const import (
     ATTR_ENTITY_PICTURE,
+    ATTR_FRIENDLY_NAME,
     ATTR_ICON,
     EVENT_COMPONENT_LOADED,
     EVENT_HOMEASSISTANT_START,
@@ -983,6 +984,7 @@ async def test_self_referencing_sensor_with_icon_and_picture_entity_loop(
                     "test": {
                         "value_template": "{{ 1 }}",
                         "entity_picture_template": "{{ ((states.sensor.test.attributes['entity_picture'] or 0) | int) + 1 }}",
+                        "friendly_name_template": "{{ ((states.sensor.test.attributes['friendly_name'] or 0) | int) + 1 }}",
                     },
                 },
             }
@@ -1007,7 +1009,8 @@ async def test_self_referencing_entity_picture_loop(
 
     state = hass.states.get("sensor.test")
     assert int(state.state) == 1
-    assert state.attributes[ATTR_ENTITY_PICTURE] == 2
+    assert state.attributes[ATTR_ENTITY_PICTURE] == "3"
+    assert state.attributes[ATTR_FRIENDLY_NAME] == "3"
 
     await hass.async_block_till_done()
     assert int(state.state) == 1