diff --git a/homeassistant/components/knocki/strings.json b/homeassistant/components/knocki/strings.json
index 8f5d0161166..8e6fb722281 100644
--- a/homeassistant/components/knocki/strings.json
+++ b/homeassistant/components/knocki/strings.json
@@ -10,6 +10,7 @@
     },
     "error": {
       "cannot_connect": "[%key:common::config_flow::error::cannot_connect%]",
+      "invalid_auth": "[%key:common::config_flow::error::invalid_auth%]",
       "unknown": "[%key:common::config_flow::error::unknown%]"
     },
     "abort": {