diff --git a/meshtastic/serial_interface.py b/meshtastic/serial_interface.py
index 4f8ddf3..90b6922 100644
--- a/meshtastic/serial_interface.py
+++ b/meshtastic/serial_interface.py
@@ -6,8 +6,8 @@ import os
 import stat
 import serial
 
+import meshtastic.util
 from .stream_interface import StreamInterface
-from .util import findPorts, our_exit
 
 class SerialInterface(StreamInterface):
     """Interface class for meshtastic devices over a serial link"""
@@ -22,14 +22,14 @@ class SerialInterface(StreamInterface):
         """
 
         if devPath is None:
-            ports = findPorts()
+            ports = meshtastic.util.findPorts()
             logging.debug(f"ports:{ports}")
             if len(ports) == 0:
-                our_exit("Warning: No Meshtastic devices detected.")
+                meshtastic.util.our_exit("Warning: No Meshtastic devices detected.")
             elif len(ports) > 1:
                 message = "Warning: Multiple serial ports were detected so one serial port must be specified with the '--port'.\n"
                 message += f"  Ports detected:{ports}"
-                our_exit(message)
+                meshtastic.util.our_exit(message)
             else:
                 devPath = ports[0]
 
diff --git a/meshtastic/test/test_serial_interface.py b/meshtastic/test/test_serial_interface.py
new file mode 100644
index 0000000..df6f12f
--- /dev/null
+++ b/meshtastic/test/test_serial_interface.py
@@ -0,0 +1,18 @@
+"""Meshtastic unit tests for serial_interface.py"""
+
+from unittest.mock import patch
+import pytest
+
+from ..serial_interface import SerialInterface
+
+@pytest.mark.unit
+@patch('serial.Serial')
+@patch('meshtastic.util.findPorts', return_value=['/dev/ttyUSBfake'])
+def test_SerialInterface(mocked_findPorts, mocked_serial):
+    """Test that we can instantiate a SerialInterface"""
+    iface = SerialInterface(noProto=True)
+    iface.showInfo()
+    iface.localNode.showInfo()
+    iface.close()
+    mocked_findPorts.assert_called()
+    mocked_serial.assert_called()