diff --git a/tunnel/mode.go b/tunnel/mode.go
index a1697a32b0..9c3e0fc0d4 100644
--- a/tunnel/mode.go
+++ b/tunnel/mode.go
@@ -58,11 +58,11 @@ func (m TunnelMode) MarshalYAML() (any, error) {
 func (m TunnelMode) String() string {
 	switch m {
 	case Global:
-		return "global"
+		return "GLOBAL"
 	case Rule:
-		return "rule"
+		return "RULE"
 	case Direct:
-		return "direct"
+		return "DIRECT"
 	default:
 		return "Unknown"
 	}