diff --git a/homeassistant/components/config/automation.py b/homeassistant/components/config/automation.py
index 01e22297c0d..f1a2d9aab84 100644
--- a/homeassistant/components/config/automation.py
+++ b/homeassistant/components/config/automation.py
@@ -1,5 +1,4 @@
 """Provide configuration end points for Automations."""
-from collections import OrderedDict
 import uuid
 
 from homeassistant.components.automation.config import (
@@ -52,7 +51,18 @@ class EditAutomationConfigView(EditIdBasedConfigView):
 
     def _write_value(self, hass, data, config_key, new_value):
         """Set value."""
-        index = None
+        updated_value = {CONF_ID: config_key}
+
+        # Iterate through some keys that we want to have ordered in the output
+        for key in ("alias", "description", "trigger", "condition", "action"):
+            if key in new_value:
+                updated_value[key] = new_value[key]
+
+        # We cover all current fields above, but just in case we start
+        # supporting more fields in the future.
+        updated_value.update(new_value)
+
+        updated = False
         for index, cur_value in enumerate(data):
             # When people copy paste their automations to the config file,
             # they sometimes forget to add IDs. Fix it here.
@@ -60,23 +70,8 @@ class EditAutomationConfigView(EditIdBasedConfigView):
                 cur_value[CONF_ID] = uuid.uuid4().hex
 
             elif cur_value[CONF_ID] == config_key:
-                break
-        else:
-            cur_value = OrderedDict()
-            cur_value[CONF_ID] = config_key
-            index = len(data)
-            data.append(cur_value)
+                data[index] = updated_value
+                updated = True
 
-        # Iterate through some keys that we want to have ordered in the output
-        updated_value = OrderedDict()
-        for key in ("id", "alias", "description", "trigger", "condition", "action"):
-            if key in cur_value:
-                updated_value[key] = cur_value[key]
-            if key in new_value:
-                updated_value[key] = new_value[key]
-
-        # We cover all current fields above, but just in case we start
-        # supporting more fields in the future.
-        updated_value.update(cur_value)
-        updated_value.update(new_value)
-        data[index] = updated_value
+        if not updated:
+            data.append(updated_value)
diff --git a/homeassistant/components/config/scene.py b/homeassistant/components/config/scene.py
index 41b8dce0957..6523ff84158 100644
--- a/homeassistant/components/config/scene.py
+++ b/homeassistant/components/config/scene.py
@@ -47,8 +47,8 @@ class EditSceneConfigView(EditIdBasedConfigView):
 
     def _write_value(self, hass, data, config_key, new_value):
         """Set value."""
-        # Iterate through some keys that we want to have ordered in the output
         updated_value = {CONF_ID: config_key}
+        # Iterate through some keys that we want to have ordered in the output
         for key in ("name", "entities"):
             if key in new_value:
                 updated_value[key] = new_value[key]
diff --git a/tests/components/config/test_automation.py b/tests/components/config/test_automation.py
index 80ee38350aa..6f782fdbbff 100644
--- a/tests/components/config/test_automation.py
+++ b/tests/components/config/test_automation.py
@@ -80,6 +80,43 @@ async def test_update_device_config(hass, hass_client, setup_automation):
     assert written[0] == orig_data
 
 
+@pytest.mark.parametrize("automation_config", ({},))
+async def test_update_remove_key_device_config(hass, hass_client, setup_automation):
+    """Test updating device config while removing a key."""
+    with patch.object(config, "SECTIONS", ["automation"]):
+        await async_setup_component(hass, "config", {})
+
+    client = await hass_client()
+
+    orig_data = [{"id": "sun", "key": "value"}, {"id": "moon", "key": "value"}]
+
+    def mock_read(path):
+        """Mock reading data."""
+        return orig_data
+
+    written = []
+
+    def mock_write(path, data):
+        """Mock writing data."""
+        written.append(data)
+
+    with patch("homeassistant.components.config._read", mock_read), patch(
+        "homeassistant.components.config._write", mock_write
+    ), patch("homeassistant.config.async_hass_config_yaml", return_value={}):
+        resp = await client.post(
+            "/api/config/automation/config/moon",
+            data=json.dumps({"trigger": [], "action": [], "condition": []}),
+        )
+
+    assert resp.status == HTTPStatus.OK
+    result = await resp.json()
+    assert result == {"result": "ok"}
+
+    assert list(orig_data[1]) == ["id", "trigger", "condition", "action"]
+    assert orig_data[1] == {"id": "moon", "trigger": [], "condition": [], "action": []}
+    assert written[0] == orig_data
+
+
 @pytest.mark.parametrize("automation_config", ({},))
 async def test_bad_formatted_automations(hass, hass_client, setup_automation):
     """Test that we handle automations without ID."""