diff --git a/agent/xds/testdata/listeners/terminating-gateway-service-subsets.latest.golden b/agent/xds/testdata/listeners/terminating-gateway-service-subsets.latest.golden
index 3d7cabb887..fea8b47757 100644
--- a/agent/xds/testdata/listeners/terminating-gateway-service-subsets.latest.golden
+++ b/agent/xds/testdata/listeners/terminating-gateway-service-subsets.latest.golden
@@ -184,7 +184,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,
@@ -266,7 +266,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,
@@ -348,7 +348,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,
diff --git a/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway-with-service-resolvers.latest.golden b/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway-with-service-resolvers.latest.golden
index 51ca730bc4..158ea619c4 100644
--- a/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway-with-service-resolvers.latest.golden
+++ b/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway-with-service-resolvers.latest.golden
@@ -130,7 +130,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,
@@ -220,7 +220,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,
@@ -364,7 +364,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,
diff --git a/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway.latest.golden b/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway.latest.golden
index ad93b113d9..f30e7e8758 100644
--- a/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway.latest.golden
+++ b/agent/xds/testdata/serverless_plugin/listeners/lambda-terminating-gateway.latest.golden
@@ -184,7 +184,7 @@
               "name": "envoy.filters.network.http_connection_manager",
               "typedConfig": {
                 "@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager",
-                "forwardClientCertDetails": "ALWAYS_FORWARD_ONLY",
+                "forwardClientCertDetails": "APPEND_FORWARD",
                 "setCurrentClientCertDetails": {
                   "cert": true,
                   "chain": true,