diff --git a/internal/pkg/config/config.go b/internal/pkg/config/config.go
index 4c1ba9018..a64884e67 100644
--- a/internal/pkg/config/config.go
+++ b/internal/pkg/config/config.go
@@ -8,6 +8,7 @@ package config
 import (
 	"context"
 	"errors"
+	"slices"
 	"strings"
 	"sync"
 
@@ -248,8 +249,9 @@ func (c *Config) Redact() *Config {
 }
 
 func checkDeprecatedOptions(deprecatedOpts map[string]string, c *ucfg.Config) {
+	keys := c.FlattenedKeys()
 	for opt, message := range deprecatedOpts {
-		if c.HasField(opt) {
+		if slices.Contains(keys, opt) {
 			zerolog.Ctx(context.TODO()).Warn().Msg(message) // TODO is used as this may be called before logger config is read.
 		}
 	}