diff --git a/homeassistant/helpers/config_validation.py b/homeassistant/helpers/config_validation.py
index ad514e044aa..0a65fa96354 100644
--- a/homeassistant/helpers/config_validation.py
+++ b/homeassistant/helpers/config_validation.py
@@ -828,6 +828,12 @@ def custom_serializer(schema: Any) -> Any:
     if schema is positive_time_period_dict:
         return {"type": "positive_time_period_dict"}
 
+    if schema is string:
+        return {"type": "string"}
+
+    if schema is boolean:
+        return {"type": "boolean"}
+
     if isinstance(schema, multi_select):
         return {"type": "multi_select", "options": schema.options}
 
diff --git a/tests/helpers/test_config_validation.py b/tests/helpers/test_config_validation.py
index f7d7acbb08e..d8956c143df 100644
--- a/tests/helpers/test_config_validation.py
+++ b/tests/helpers/test_config_validation.py
@@ -571,6 +571,27 @@ def test_multi_select_in_serializer():
     }
 
 
+def test_boolean_in_serializer():
+    """Test boolean with custom_serializer."""
+    assert cv.custom_serializer(cv.boolean) == {
+        "type": "boolean",
+    }
+
+
+def test_string_in_serializer():
+    """Test string with custom_serializer."""
+    assert cv.custom_serializer(cv.string) == {
+        "type": "string",
+    }
+
+
+def test_positive_time_period_dict_in_serializer():
+    """Test positive_time_period_dict with custom_serializer."""
+    assert cv.custom_serializer(cv.positive_time_period_dict) == {
+        "type": "positive_time_period_dict",
+    }
+
+
 @pytest.fixture
 def schema():
     """Create a schema used for testing deprecation."""