diff --git a/controllers/spec/utils.go b/controllers/spec/utils.go
index 2f8958020..3b041c703 100644
--- a/controllers/spec/utils.go
+++ b/controllers/spec/utils.go
@@ -32,6 +32,10 @@ import (
 	"github.com/streamnative/function-mesh/controllers/proto"
 )
 
+const (
+	DefaultParallelism = 1
+)
+
 func convertFunctionDetails(function *v1alpha1.Function) *proto.FunctionDetails {
 	fd := &proto.FunctionDetails{
 		Tenant:               function.Spec.Tenant,
@@ -43,7 +47,7 @@ func convertFunctionDetails(function *v1alpha1.Function) *proto.FunctionDetails
 		UserConfig:           getUserConfig(function.Spec.FuncConfig),
 		Runtime:              proto.FunctionDetails_JAVA,
 		AutoAck:              getBoolFromPtrOrDefault(function.Spec.AutoAck, true),
-		Parallelism:          getInt32FromPtrOrDefault(function.Spec.Replicas, 1),
+		Parallelism:          DefaultParallelism,
 		Source:               generateFunctionInputSpec(function),
 		Sink:                 generateFunctionOutputSpec(function),
 		Resources:            generateResource(function.Spec.Resources.Requests),
@@ -80,7 +84,7 @@ func convertGoFunctionConfs(function *v1alpha1.Function) *GoFunctionConf {
 		//SecretsMap:                  marshalSecretsMap(function.Spec.SecretsMap),
 		Runtime:                     int32(proto.FunctionDetails_GO),
 		AutoACK:                     getBoolFromPtrOrDefault(function.Spec.AutoAck, true),
-		Parallelism:                 getInt32FromPtrOrDefault(function.Spec.Replicas, 1),
+		Parallelism:                 DefaultParallelism,
 		TimeoutMs:                   uint64(function.Spec.Timeout),
 		SubscriptionName:            function.Spec.SubscriptionName,
 		CleanupSubscription:         function.Spec.CleanupSubscription,
@@ -217,7 +221,7 @@ func convertSourceDetails(source *v1alpha1.Source) *proto.FunctionDetails {
 		UserConfig:           getUserConfig(source.Spec.SourceConfig),
 		Runtime:              proto.FunctionDetails_JAVA,
 		AutoAck:              true,
-		Parallelism:          getInt32FromPtrOrDefault(source.Spec.Replicas, 1),
+		Parallelism:          DefaultParallelism,
 		Source:               generateSourceInputSpec(source),
 		Sink:                 generateSourceOutputSpec(source),
 		Resources:            generateResource(source.Spec.Resources.Requests),
@@ -279,7 +283,7 @@ func convertSinkDetails(sink *v1alpha1.Sink) *proto.FunctionDetails {
 		ProcessingGuarantees: convertProcessingGuarantee(sink.Spec.ProcessingGuarantee),
 		Runtime:              proto.FunctionDetails_JAVA,
 		AutoAck:              getBoolFromPtrOrDefault(sink.Spec.AutoAck, true),
-		Parallelism:          getInt32FromPtrOrDefault(sink.Spec.Replicas, 1),
+		Parallelism:          DefaultParallelism,
 		Source:               generateSinkInputSpec(sink),
 		Sink:                 generateSinkOutputSpec(sink),
 		Resources:            generateResource(sink.Spec.Resources.Requests),