diff --git a/homeassistant/components/cast/config_flow.py b/homeassistant/components/cast/config_flow.py
index 464283e07f3..86d85588967 100644
--- a/homeassistant/components/cast/config_flow.py
+++ b/homeassistant/components/cast/config_flow.py
@@ -133,7 +133,7 @@ class CastOptionsFlowHandler(config_entries.OptionsFlow):
             )
 
             if not bad_cec and not bad_hosts and not bad_uuid:
-                updated_config = {}
+                updated_config = dict(current_config)
                 updated_config[CONF_IGNORE_CEC] = ignore_cec
                 updated_config[CONF_KNOWN_HOSTS] = known_hosts
                 updated_config[CONF_UUID] = wanted_uuid
diff --git a/tests/components/cast/test_config_flow.py b/tests/components/cast/test_config_flow.py
index 064406df717..1febd9d8803 100644
--- a/tests/components/cast/test_config_flow.py
+++ b/tests/components/cast/test_config_flow.py
@@ -166,6 +166,7 @@ async def test_option_flow(hass, parameter_data):
     assert result["step_id"] == "options"
     data_schema = result["data_schema"].schema
     assert set(data_schema) == {"known_hosts"}
+    orig_data = dict(config_entry.data)
 
     # Reconfigure ignore_cec, known_hosts, uuid
     context = {"source": "user", "show_advanced_options": True}
@@ -201,7 +202,12 @@ async def test_option_flow(hass, parameter_data):
     )
     assert result["type"] == data_entry_flow.RESULT_TYPE_CREATE_ENTRY
     assert result["data"] is None
-    assert config_entry.data == {"ignore_cec": [], "known_hosts": [], "uuid": []}
+    assert config_entry.data == {
+        **orig_data,
+        "ignore_cec": [],
+        "known_hosts": [],
+        "uuid": [],
+    }
 
 
 async def test_known_hosts(hass, castbrowser_mock, castbrowser_constructor_mock):