diff --git a/homeassistant/components/smlight/config_flow.py b/homeassistant/components/smlight/config_flow.py
index e8984300ff1..0e5b0f49d7b 100644
--- a/homeassistant/components/smlight/config_flow.py
+++ b/homeassistant/components/smlight/config_flow.py
@@ -97,8 +97,13 @@ class SmlightConfigFlow(ConfigFlow, domain=DOMAIN):
         mac = discovery_info.properties.get("mac")
         # fallback for legacy firmware
         if mac is None:
-            info = await self.client.get_info()
+            try:
+                info = await self.client.get_info()
+            except SmlightConnectionError:
+                # User is likely running unsupported ESPHome firmware
+                return self.async_abort(reason="cannot_connect")
             mac = info.MAC
+
         await self.async_set_unique_id(format_mac(mac))
         self._abort_if_unique_id_configured()
 
diff --git a/tests/components/smlight/test_config_flow.py b/tests/components/smlight/test_config_flow.py
index dae727c7a29..2fd39f75704 100644
--- a/tests/components/smlight/test_config_flow.py
+++ b/tests/components/smlight/test_config_flow.py
@@ -336,6 +336,22 @@ async def test_zeroconf_cannot_connect(
     assert result2["reason"] == "cannot_connect"
 
 
+async def test_zeroconf_legacy_cannot_connect(
+    hass: HomeAssistant, mock_smlight_client: MagicMock
+) -> None:
+    """Test we abort flow on zeroconf discovery unsupported firmware."""
+    mock_smlight_client.get_info.side_effect = SmlightConnectionError
+
+    result = await hass.config_entries.flow.async_init(
+        DOMAIN,
+        context={"source": SOURCE_ZEROCONF},
+        data=DISCOVERY_INFO_LEGACY,
+    )
+
+    assert result["type"] is FlowResultType.ABORT
+    assert result["reason"] == "cannot_connect"
+
+
 @pytest.mark.usefixtures("mock_smlight_client")
 async def test_zeroconf_legacy_mac(
     hass: HomeAssistant, mock_smlight_client: MagicMock, mock_setup_entry: AsyncMock