diff --git a/docs/content/observability/access-logs.md b/docs/content/observability/access-logs.md
index 2c00e9dd2..5e6551a51 100644
--- a/docs/content/observability/access-logs.md
+++ b/docs/content/observability/access-logs.md
@@ -26,12 +26,11 @@ accessLog: {}
 By default access logs are written to the standard output.
 To write the logs into a log file, use the `filePath` option.
 
-in the Common Log Format (CLF), extended with additional fields.
-
 ### `format`
  
 By default, logs are written using the Common Log Format (CLF).
 To write logs in JSON, use `json` in the `format` option.
+If the given format is unsupported, the default (CLF) is used instead.
 
 !!! note "Common Log Format"
     
diff --git a/pkg/middlewares/accesslog/logger.go b/pkg/middlewares/accesslog/logger.go
index 4cce7fe06..1f6b80b4b 100644
--- a/pkg/middlewares/accesslog/logger.go
+++ b/pkg/middlewares/accesslog/logger.go
@@ -77,7 +77,8 @@ func NewHandler(config *types.AccessLog) (*Handler, error) {
 	case JSONFormat:
 		formatter = new(logrus.JSONFormatter)
 	default:
-		return nil, fmt.Errorf("unsupported access log format: %s", config.Format)
+		log.WithoutContext().Errorf("unsupported access log format: %q, defaulting to common format instead.", config.Format)
+		formatter = new(CommonLogFormatter)
 	}
 
 	logger := &logrus.Logger{