diff --git a/charger/easee.go b/charger/easee.go
index f246a09bd..0b0a9ad4e 100644
--- a/charger/easee.go
+++ b/charger/easee.go
@@ -227,9 +227,9 @@ func (c *Easee) connect(ts oauth2.TokenSource) func() (signalr.Connection, error
 
 		return signalr.NewHTTPConnection(ctx, "https://streams.easee.com/hubs/chargers",
 			signalr.WithHTTPClient(c.Client),
-			signalr.WithHTTPHeaders(func() (res http.Header) {
+			signalr.WithHTTPHeaders(func() http.Header {
 				return http.Header{
-					"Authorization": []string{fmt.Sprintf("Bearer %s", tok.AccessToken)},
+					"Authorization": []string{"Bearer " + tok.AccessToken},
 				}
 			}),
 		)
diff --git a/charger/mcc.go b/charger/mcc.go
index d3784247c..bc1a3fe19 100644
--- a/charger/mcc.go
+++ b/charger/mcc.go
@@ -148,7 +148,7 @@ func (mcc *MobileConnect) refresh() error {
 	}
 
 	req.Header.Set("Referer", fmt.Sprintf("%s/login", mcc.uri))
-	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", mcc.token))
+	req.Header.Set("Authorization", "Bearer "+mcc.token)
 
 	return mcc.fetchToken(req)
 }
@@ -181,7 +181,7 @@ func (mcc *MobileConnect) request(method, uri string) (*http.Request, error) {
 		return req, err
 	}
 
-	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", mcc.token))
+	req.Header.Set("Authorization", "Bearer "+mcc.token)
 	req.Header.Set("Referer", fmt.Sprintf("%s/dashboard", mcc.uri))
 
 	return req, nil
diff --git a/tariff/amber.go b/tariff/amber.go
index 837b23c12..c76b5f5cf 100644
--- a/tariff/amber.go
+++ b/tariff/amber.go
@@ -69,7 +69,7 @@ func NewAmberFromConfig(other map[string]interface{}) (api.Tariff, error) {
 	t.Client.Transport = &transport.Decorator{
 		Base: t.Client.Transport,
 		Decorator: transport.DecorateHeaders(map[string]string{
-			"Authorization": fmt.Sprintf("Bearer %s", cc.Token),
+			"Authorization": "Bearer " + cc.Token,
 		}),
 	}