diff --git a/_examples/cluster-reentrancy/hello_grain.pb.go b/_examples/cluster-reentrancy/hello_grain.pb.go
index e6335e9e..1aed4d75 100644
--- a/_examples/cluster-reentrancy/hello_grain.pb.go
+++ b/_examples/cluster-reentrancy/hello_grain.pb.go
@@ -1,12 +1,13 @@
 // Code generated by protoc-gen-grain. DO NOT EDIT.
 // versions:
-//  protoc-gen-grain v0.3.0
+//  protoc-gen-grain v0.4.0
 //  protoc           v4.25.0
 // source: hello.proto
 
 package main
 
 import (
+	errors "errors"
 	fmt "fmt"
 	actor "github.com/asynkron/protoactor-go/actor"
 	cluster "github.com/asynkron/protoactor-go/cluster"
@@ -101,8 +102,8 @@ func (g *HelloGrainClient) InvokeService(r *InvokeServiceRequest, opts ...cluste
 	switch msg := resp.(type) {
 	case *InvokeServiceResponse:
 		return msg, nil
-	case error:
-		return nil, fmt.Errorf("error response: %w", msg)
+	case *cluster.GrainErrorResponse:
+		return nil, errors.New(msg.Err)
 	default:
 		return nil, fmt.Errorf("unknown response type %T", resp)
 	}
@@ -138,8 +139,8 @@ func (g *HelloGrainClient) DoWork(r *DoWorkRequest, opts ...cluster.GrainCallOpt
 	switch msg := resp.(type) {
 	case *DoWorkResponse:
 		return msg, nil
-	case error:
-		return nil, fmt.Errorf("error response: %w", msg)
+	case *cluster.GrainErrorResponse:
+		return nil, errors.New(msg.Err)
 	default:
 		return nil, fmt.Errorf("unknown response type %T", resp)
 	}
@@ -178,12 +179,14 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 			err := proto.Unmarshal(msg.MessageData, req)
 			if err != nil {
 				ctx.Logger().Error("[Grain] InvokeService(InvokeServiceRequest) proto.Unmarshal failed.", slog.Any("error", err))
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			err = a.inner.InvokeService(req, respond[*InvokeServiceResponse](a.ctx), a.onError, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 		case 1:
@@ -191,13 +194,15 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 			err := proto.Unmarshal(msg.MessageData, req)
 			if err != nil {
 				ctx.Logger().Error("[Grain] DoWork(DoWorkRequest) proto.Unmarshal failed.", slog.Any("error", err))
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 
 			r0, err := a.inner.DoWork(req, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			ctx.Respond(r0)
@@ -210,7 +215,8 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 // onError should be used in ctx.ReenterAfter
 // you can just return error in reenterable method for other errors
 func (a *HelloActor) onError(err error) {
-	a.ctx.Respond(err)
+	resp := &cluster.GrainErrorResponse{Err: err.Error()}
+	a.ctx.Respond(resp)
 }
 
 func respond[T proto.Message](ctx cluster.GrainContext) func(T) {
diff --git a/_examples/cluster-reentrancy/main.go b/_examples/cluster-reentrancy/main.go
index d6dc29ae..5fa4cf0e 100644
--- a/_examples/cluster-reentrancy/main.go
+++ b/_examples/cluster-reentrancy/main.go
@@ -18,11 +18,10 @@ func main() {
 	helloKind := NewHelloKind(NewHelloGrain, 0)
 	clusterConfig := cluster.Configure("core", provider, lookup, config, cluster.WithKinds(
 		helloKind))
-	cluster := cluster.New(system, clusterConfig)
-	cluster.StartMember()
-
+	cst := cluster.New(system, clusterConfig)
+	cst.StartMember()
 	// self call: request -> 1 -> 1
-	client := GetHelloGrainClient(cluster, "1")
+	client := GetHelloGrainClient(cst, "1")
 	resp, err := client.InvokeService(&InvokeServiceRequest{Name: "Alice"})
 	if err != nil {
 		panic(err)
@@ -30,7 +29,7 @@ func main() {
 	fmt.Printf("%v\n", resp)
 
 	// reenter call: request -> 2 -> 1 -> 2
-	client = GetHelloGrainClient(cluster, "2")
+	client = GetHelloGrainClient(cst, "2")
 	resp, err = client.InvokeService(&InvokeServiceRequest{Name: "Alice"})
 	if err != nil {
 		panic(err)
diff --git a/protobuf/protoc-gen-go-grain/generate.go b/protobuf/protoc-gen-go-grain/generate.go
index 12aea1ca..9753e9b8 100644
--- a/protobuf/protoc-gen-go-grain/generate.go
+++ b/protobuf/protoc-gen-go-grain/generate.go
@@ -66,6 +66,7 @@ func generateContent(gen *protogen.Plugin, g *protogen.GeneratedFile, file *prot
 	g.QualifiedGoIdent(fmtPackage.Ident(""))
 	g.QualifiedGoIdent(timePackage.Ident(""))
 	g.QualifiedGoIdent(slogPackage.Ident(""))
+	g.QualifiedGoIdent(errorsPackage.Ident(""))
 
 	for _, service := range file.Services {
 		generateService(service, file, g)
diff --git a/protobuf/protoc-gen-go-grain/templates/grain.tmpl b/protobuf/protoc-gen-go-grain/templates/grain.tmpl
index 300973f3..b2fec6f2 100644
--- a/protobuf/protoc-gen-go-grain/templates/grain.tmpl
+++ b/protobuf/protoc-gen-go-grain/templates/grain.tmpl
@@ -91,8 +91,8 @@ func (g *{{ $service.Name }}GrainClient) {{ $method.Name }}(r *{{ $method.Input
 	switch msg := resp.(type) {
 	case *{{ $method.Output }}:
 		return msg, nil
-	case error:
-		return nil, fmt.Errorf("error response: %w", msg)
+	case *cluster.GrainErrorResponse:
+		return nil, errors.New(msg.Err)
 	default:
 		return nil, fmt.Errorf("unknown response type %T", resp)
 	}
@@ -132,19 +132,22 @@ func (a *{{ $service.Name }}Actor) Receive(ctx actor.Context) {
 			err := proto.Unmarshal(msg.MessageData, req)
 			if err != nil {
 				ctx.Logger().Error("[Grain] {{ $method.Name }}({{ $method.Input }}) proto.Unmarshal failed.", slog.Any("error", err))
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			{{ if $method.Options.Reenterable -}}
 			err = a.inner.{{ $method.Name }}(req, respond[*{{ $method.Output }}](a.ctx), a.onError, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			{{ else }}
 			r0, err := a.inner.{{ $method.Name }}(req, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			ctx.Respond(r0)
@@ -159,7 +162,8 @@ func (a *{{ $service.Name }}Actor) Receive(ctx actor.Context) {
 // onError should be used in ctx.ReenterAfter
 // you can just return error in reenterable method for other errors
 func (a *{{ $service.Name }}Actor) onError(err error) {
-	a.ctx.Respond(err)
+	resp := &cluster.GrainErrorResponse{Err: err.Error()}
+	a.ctx.Respond(resp)
 }
 
 func respond[T proto.Message](ctx cluster.GrainContext) func (T) {
diff --git a/protobuf/protoc-gen-go-grain/testdata/hello/hello_grain.pb.go b/protobuf/protoc-gen-go-grain/testdata/hello/hello_grain.pb.go
index 82da47e2..5d3c67c8 100644
--- a/protobuf/protoc-gen-go-grain/testdata/hello/hello_grain.pb.go
+++ b/protobuf/protoc-gen-go-grain/testdata/hello/hello_grain.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-grain. DO NOT EDIT.
 // versions:
-//  protoc-gen-grain v0.3.0
+//  protoc-gen-grain v0.4.0
 //  protoc           v4.25.0
 // source: testdata/hello/hello.proto
 
@@ -85,8 +85,8 @@ func (g *HelloGrainClient) SayHello(r *emptypb.Empty, opts ...cluster.GrainCallO
 	switch msg := resp.(type) {
 	case *SayHelloResponse:
 		return msg, nil
-	case error:
-		return nil, fmt.Errorf("error response: %w", msg)
+	case *cluster.GrainErrorResponse:
+		return nil, errors.New(msg.Err)
 	default:
 		return nil, fmt.Errorf("unknown response type %T", resp)
 	}
@@ -125,13 +125,15 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 			err := proto.Unmarshal(msg.MessageData, req)
 			if err != nil {
 				ctx.Logger().Error("[Grain] SayHello(emptypb.Empty) proto.Unmarshal failed.", slog.Any("error", err))
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 
 			r0, err := a.inner.SayHello(req, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			ctx.Respond(r0)
@@ -144,7 +146,8 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 // onError should be used in ctx.ReenterAfter
 // you can just return error in reenterable method for other errors
 func (a *HelloActor) onError(err error) {
-	a.ctx.Respond(err)
+	resp := &cluster.GrainErrorResponse{Err: err.Error()}
+	a.ctx.Respond(resp)
 }
 
 func respond[T proto.Message](ctx cluster.GrainContext) func(T) {
diff --git a/protobuf/protoc-gen-go-grain/testdata/reenter/hello_grain.pb.go b/protobuf/protoc-gen-go-grain/testdata/reenter/hello_grain.pb.go
index 366f42be..06d0c835 100644
--- a/protobuf/protoc-gen-go-grain/testdata/reenter/hello_grain.pb.go
+++ b/protobuf/protoc-gen-go-grain/testdata/reenter/hello_grain.pb.go
@@ -1,6 +1,6 @@
 // Code generated by protoc-gen-grain. DO NOT EDIT.
 // versions:
-//  protoc-gen-grain v0.3.0
+//  protoc-gen-grain v0.4.0
 //  protoc           v4.25.0
 // source: testdata/reenter/hello.proto
 
@@ -85,8 +85,8 @@ func (g *HelloGrainClient) SayHello(r *SayHelloRequest, opts ...cluster.GrainCal
 	switch msg := resp.(type) {
 	case *SayHelloResponse:
 		return msg, nil
-	case error:
-		return nil, fmt.Errorf("error response: %w", msg)
+	case *cluster.GrainErrorResponse:
+		return nil, errors.New(msg.Err)
 	default:
 		return nil, fmt.Errorf("unknown response type %T", resp)
 	}
@@ -122,8 +122,8 @@ func (g *HelloGrainClient) Dowork(r *DoworkRequest, opts ...cluster.GrainCallOpt
 	switch msg := resp.(type) {
 	case *DoworkResponse:
 		return msg, nil
-	case error:
-		return nil, fmt.Errorf("error response: %w", msg)
+	case *cluster.GrainErrorResponse:
+		return nil, errors.New(msg.Err)
 	default:
 		return nil, fmt.Errorf("unknown response type %T", resp)
 	}
@@ -162,12 +162,14 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 			err := proto.Unmarshal(msg.MessageData, req)
 			if err != nil {
 				ctx.Logger().Error("[Grain] SayHello(SayHelloRequest) proto.Unmarshal failed.", slog.Any("error", err))
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			err = a.inner.SayHello(req, respond[*SayHelloResponse](a.ctx), a.onError, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 		case 1:
@@ -175,13 +177,15 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 			err := proto.Unmarshal(msg.MessageData, req)
 			if err != nil {
 				ctx.Logger().Error("[Grain] Dowork(DoworkRequest) proto.Unmarshal failed.", slog.Any("error", err))
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 
 			r0, err := a.inner.Dowork(req, a.ctx)
 			if err != nil {
-				ctx.Respond(err)
+				resp := &cluster.GrainErrorResponse{Err: err.Error()}
+				ctx.Respond(resp)
 				return
 			}
 			ctx.Respond(r0)
@@ -194,7 +198,8 @@ func (a *HelloActor) Receive(ctx actor.Context) {
 // onError should be used in ctx.ReenterAfter
 // you can just return error in reenterable method for other errors
 func (a *HelloActor) onError(err error) {
-	a.ctx.Respond(err)
+	resp := &cluster.GrainErrorResponse{Err: err.Error()}
+	a.ctx.Respond(resp)
 }
 
 func respond[T proto.Message](ctx cluster.GrainContext) func(T) {
diff --git a/protobuf/protoc-gen-go-grain/version.go b/protobuf/protoc-gen-go-grain/version.go
index a90b5b3c..e3e9e935 100644
--- a/protobuf/protoc-gen-go-grain/version.go
+++ b/protobuf/protoc-gen-go-grain/version.go
@@ -1,3 +1,3 @@
 package main
 
-const version = "v0.3.0"
+const version = "v0.4.0"