diff --git a/internal/configs/ingress.go b/internal/configs/ingress.go
index e19bd37d83..ff09975fba 100644
--- a/internal/configs/ingress.go
+++ b/internal/configs/ingress.go
@@ -512,8 +512,9 @@ func createUpstream(ingEx *IngressEx, name string, backend *networking.IngressBa
 		}
 
 		if cfg.UseClusterIP {
+			fqdn := fmt.Sprintf("%s.%s.svc.cluster.local:%d", backend.Service.Name, ingEx.Ingress.Namespace, backend.Service.Port.Number)
 			upsServers = append(upsServers, version1.UpstreamServer{
-				Address:     fmt.Sprintf("%s:%d", backend.Service.Name, backend.Service.Port.Number),
+				Address:     fqdn,
 				MaxFails:    cfg.MaxFails,
 				MaxConns:    cfg.MaxConns,
 				FailTimeout: cfg.FailTimeout,
diff --git a/internal/configs/ingress_test.go b/internal/configs/ingress_test.go
index ea68e6cb5b..decf9f4a2f 100644
--- a/internal/configs/ingress_test.go
+++ b/internal/configs/ingress_test.go
@@ -700,7 +700,7 @@ func createExpectedConfigForMergeableCafeIngressWithUseClusterIP() version1.Ingr
 		UpstreamZoneSize: upstreamZoneSize,
 		UpstreamServers: []version1.UpstreamServer{
 			{
-				Address:     "coffee-svc:80",
+				Address:     "coffee-svc.default.svc.cluster.local:80",
 				MaxFails:    1,
 				MaxConns:    0,
 				FailTimeout: "10s",
@@ -803,7 +803,7 @@ func createExpectedConfigForCafeIngressWithUseClusterIP() version1.IngressNginxC
 		UpstreamZoneSize: upstreamZoneSize,
 		UpstreamServers: []version1.UpstreamServer{
 			{
-				Address:     "coffee-svc:80",
+				Address:     "coffee-svc.default.svc.cluster.local:80",
 				MaxFails:    1,
 				MaxConns:    0,
 				FailTimeout: "10s",
@@ -817,7 +817,7 @@ func createExpectedConfigForCafeIngressWithUseClusterIP() version1.IngressNginxC
 		UpstreamZoneSize: upstreamZoneSize,
 		UpstreamServers: []version1.UpstreamServer{
 			{
-				Address:     "tea-svc:80",
+				Address:     "tea-svc.default.svc.cluster.local:80",
 				MaxFails:    1,
 				MaxConns:    0,
 				FailTimeout: "10s",