diff --git a/VERSION b/VERSION
index 26ca594..4bb2004 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-1.5.1
+1.5.2-dev
diff --git a/internal/bbsim/api/grpc_api_server.go b/internal/bbsim/api/grpc_api_server.go
index 5fd6392..01c7f4f 100644
--- a/internal/bbsim/api/grpc_api_server.go
+++ b/internal/bbsim/api/grpc_api_server.go
@@ -149,10 +149,15 @@
 
 	logger.Infof("Received request to start Openolt gRPC Server")
 
-	_, err := o.StartOltServer()
+	if o.OltServer != nil {
+		return nil, fmt.Errorf("Openolt gRPC server already running.")
+	}
+
+	oltGrpcServer, err := o.StartOltServer()
 	if err != nil {
 		return nil, err
 	}
+	o.OltServer = oltGrpcServer
 
 	return res, nil
 }
@@ -168,12 +173,13 @@
 
 	go func() {
 		time.Sleep(time.Duration(req.Delay) * time.Second)
-		_, err := o.StartOltServer()
+		oltGrpcServer, err := o.StartOltServer()
 		if err != nil {
 			logger.WithFields(log.Fields{
 				"err": err,
 			}).Error("Cannot restart Openolt gRPC server")
 		}
+		o.OltServer = oltGrpcServer
 		logger.Infof("Openolt gRPC Server restarted after %v seconds", req.Delay)
 	}()
 
diff --git a/internal/bbsim/devices/olt.go b/internal/bbsim/devices/olt.go
index b2c82d9..f6a4b40 100644
--- a/internal/bbsim/devices/olt.go
+++ b/internal/bbsim/devices/olt.go
@@ -49,7 +49,7 @@
 
 type OltDevice struct {
 	sync.Mutex
-	oltServer *grpc.Server
+	OltServer *grpc.Server
 
 	// BBSIM Internals
 	ID                   int
@@ -226,8 +226,8 @@
 
 func (o *OltDevice) InitOlt() {
 
-	if o.oltServer == nil {
-		o.oltServer, _ = o.StartOltServer()
+	if o.OltServer == nil {
+		o.OltServer, _ = o.StartOltServer()
 	} else {
 		oltLogger.Fatal("OLT server already running.")
 	}
@@ -355,12 +355,12 @@
 
 // StopOltServer stops the OpenOLT grpc server
 func (o *OltDevice) StopOltServer() {
-	if o.oltServer != nil {
+	if o.OltServer != nil {
 		oltLogger.WithFields(log.Fields{
 			"oltId": o.SerialNumber,
 		}).Warnf("Stopping OLT gRPC server")
-		o.oltServer.Stop()
-		o.oltServer = nil
+		o.OltServer.Stop()
+		o.OltServer = nil
 	}
 }