diff --git a/plugin/auth/viessmann.go b/plugin/auth/viessmann.go
index 9343acdb8..0c7a8a98b 100644
--- a/plugin/auth/viessmann.go
+++ b/plugin/auth/viessmann.go
@@ -28,7 +28,7 @@ func NewViessmannFromConfig(ctx context.Context, other map[string]any) (oauth2.T
 	var cc struct {
 		ClientID    string
 		RedirectURI string
-		Gateway     string
+		Gateway     string `mapstructure:"gateway_serial"`
 	}
 
 	if err := util.DecodeOther(other, &cc); err != nil {
diff --git a/templates/definition/charger/viessmann.yaml b/templates/definition/charger/viessmann.yaml
index db8d867b4..7845b1de8 100644
--- a/templates/definition/charger/viessmann.yaml
+++ b/templates/definition/charger/viessmann.yaml
@@ -150,7 +150,7 @@ params:
     type: int
 auth:
   type: viessmann
-  params: [clientid, redirecturi, gateway]
+  params: [clientid, redirecturi, gateway_serial]
 render: |
   type: sgready
   getmode: