diff --git a/pkg/trainer/replicas.go b/pkg/trainer/replicas.go
index c3e76ac..0feef4e 100644
--- a/pkg/trainer/replicas.go
+++ b/pkg/trainer/replicas.go
@@ -211,26 +211,36 @@ func (s *MXReplicaSet) createDist() error {
 			if spec.ContainerName(c.Name) != spec.MXNET {
 				continue
 			}
-			if len(c.Env) == 0 {
-				c.Env = make([]v1.EnvVar, 5)
+			if c.Env == nil {
+				c.Env = []v1.EnvVar{}
 			}
 			for _, r := range s.Job.job.Spec.ReplicaSpecs {
 				switch r.MxReplicaType {
 				case spec.SCHEDULER:
-					c.Env[0].Name = "DMLC_PS_ROOT_PORT"
-					c.Env[0].Value = strconv.Itoa(int(*r.PsRootPort))
-					c.Env[1].Name = "DMLC_PS_ROOT_URI"
-					c.Env[1].Value = fmt.Sprintf("%v-%v-%v-%v", s.Job.job.Metadata.Name, strings.ToLower(string(r.MxReplicaType)), s.Job.job.Spec.RuntimeId, 0)
+					c.Env = append(c.Env, v1.EnvVar{
+						Name: "DMLC_PS_ROOT_PORT",
+						Value: strconv.Itoa(int(*r.PsRootPort)),
+					})
+					c.Env = append(c.Env, v1.EnvVar{
+						Name: "DMLC_PS_ROOT_URI",
+						Value: fmt.Sprintf("%v-%v-%v-%v", s.Job.job.Metadata.Name, strings.ToLower(string(r.MxReplicaType)), s.Job.job.Spec.RuntimeId, 0),
+					})
 				case spec.SERVER:
-					c.Env[2].Name = "DMLC_NUM_SERVER"
-					c.Env[2].Value = strconv.Itoa(int(*r.Replicas))
+					c.Env = append(c.Env, v1.EnvVar{
+						Name: "DMLC_NUM_SERVER",
+						Value: strconv.Itoa(int(*r.Replicas)),
+					})
 				case spec.WORKER:
-					c.Env[3].Name = "DMLC_NUM_WORKER"
-					c.Env[3].Value = strconv.Itoa(int(*r.Replicas))
+					c.Env = append(c.Env, v1.EnvVar{
+						Name: "DMLC_NUM_WORKER",
+						Value: strconv.Itoa(int(*r.Replicas)),
+					})
 				}
 			}
-			c.Env[4].Name = "DMLC_ROLE"
-			c.Env[4].Value = strings.ToLower(string(s.Spec.MxReplicaType))
+			c.Env = append(c.Env, v1.EnvVar{
+				Name: "DMLC_ROLE",
+				Value: strings.ToLower(string(s.Spec.MxReplicaType)),
+			})
 		}
 
 		log.Infof("Creating Job: %v", newJ.ObjectMeta.Name)