diff --git a/util/modbus/modbus.go b/util/modbus/modbus.go
index dc0d031d0..97b9f29f0 100644
--- a/util/modbus/modbus.go
+++ b/util/modbus/modbus.go
@@ -161,7 +161,7 @@ func ProtocolFromRTU(rtu *bool) Protocol {
 }
 
 // NewConnection creates physical modbus device from config
-func NewConnection(uri, device, comset string, baudrate int, wire Protocol, slaveID uint8) (*Connection, error) {
+func NewConnection(uri, device, comset string, baudrate int, proto Protocol, slaveID uint8) (*Connection, error) {
 	var conn meters.Connection
 
 	if device != "" && uri != "" {
@@ -181,10 +181,10 @@ func NewConnection(uri, device, comset string, baudrate int, wire Protocol, slav
 			return nil, errors.New("invalid modbus configuration: need baudrate and comset")
 		}
 
-		if wire == Rtu {
-			conn = registeredConnection(device, meters.NewRTU(device, baudrate, comset))
+		if proto == Ascii {
+			conn = registeredConnection(device, meters.NewASCII(device, baudrate, comset))
 		} else {
-			conn = registeredConnection(uri, meters.NewASCII(device, baudrate, comset))
+			conn = registeredConnection(device, meters.NewRTU(device, baudrate, comset))
 		}
 	}