diff --git a/homeassistant/components/zwave_js/config_flow.py b/homeassistant/components/zwave_js/config_flow.py
index 3da785cdcf2..c114662888f 100644
--- a/homeassistant/components/zwave_js/config_flow.py
+++ b/homeassistant/components/zwave_js/config_flow.py
@@ -792,7 +792,9 @@ class OptionsFlowHandler(BaseZwaveJSFlow, config_entries.OptionsFlow):
                 CONF_ADDON_S2_AUTHENTICATED_KEY: self.s2_authenticated_key,
                 CONF_ADDON_S2_UNAUTHENTICATED_KEY: self.s2_unauthenticated_key,
                 CONF_ADDON_LOG_LEVEL: user_input[CONF_LOG_LEVEL],
-                CONF_ADDON_EMULATE_HARDWARE: user_input[CONF_EMULATE_HARDWARE],
+                CONF_ADDON_EMULATE_HARDWARE: user_input.get(
+                    CONF_EMULATE_HARDWARE, False
+                ),
             }
 
             if new_addon_config != addon_config:
diff --git a/tests/components/zwave_js/test_config_flow.py b/tests/components/zwave_js/test_config_flow.py
index 6c4b18e8dc3..d4f159f2510 100644
--- a/tests/components/zwave_js/test_config_flow.py
+++ b/tests/components/zwave_js/test_config_flow.py
@@ -1951,6 +1951,30 @@ async def different_device_server_version(*args):
             0,
             different_device_server_version,
         ),
+        (
+            {"config": ADDON_DISCOVERY_INFO},
+            {},
+            {
+                "device": "/test",
+                "network_key": "old123",
+                "s0_legacy_key": "old123",
+                "s2_access_control_key": "old456",
+                "s2_authenticated_key": "old789",
+                "s2_unauthenticated_key": "old987",
+                "log_level": "info",
+            },
+            {
+                "usb_path": "/new",
+                "s0_legacy_key": "new123",
+                "s2_access_control_key": "new456",
+                "s2_authenticated_key": "new789",
+                "s2_unauthenticated_key": "new987",
+                "log_level": "info",
+                "emulate_hardware": False,
+            },
+            0,
+            different_device_server_version,
+        ),
     ],
 )
 async def test_options_different_device(
@@ -2018,14 +2042,16 @@ async def test_options_different_device(
     result = await hass.config_entries.options.async_configure(result["flow_id"])
     await hass.async_block_till_done()
 
+    # Default emulate_hardware is False.
+    addon_options = {"emulate_hardware": False} | old_addon_options
     # Legacy network key is not reset.
-    old_addon_options.pop("network_key")
+    addon_options.pop("network_key")
 
     assert set_addon_options.call_count == 2
     assert set_addon_options.call_args == call(
         hass,
         "core_zwave_js",
-        {"options": old_addon_options},
+        {"options": addon_options},
     )
     assert result["type"] == "progress"
     assert result["step_id"] == "start_addon"