diff --git a/meshtastic/tests/test_util.py b/meshtastic/tests/test_util.py
index b933143..03cf4c9 100644
--- a/meshtastic/tests/test_util.py
+++ b/meshtastic/tests/test_util.py
@@ -249,4 +249,5 @@ def test_findPorts_when_none_found(patch_comports):
 def test_convert_mac_addr():
     """Test convert_mac_addr()"""
     assert convert_mac_addr('/c0gFyhb') == 'fd:cd:20:17:28:5b'
+    assert convert_mac_addr('fd:cd:20:17:28:5b') == 'fd:cd:20:17:28:5b'
     assert convert_mac_addr('') == ''
diff --git a/meshtastic/util.py b/meshtastic/util.py
index 0d6a837..8abbea9 100644
--- a/meshtastic/util.py
+++ b/meshtastic/util.py
@@ -3,6 +3,7 @@
 import traceback
 from queue import Queue
 import os
+import re
 import sys
 import base64
 import time
@@ -238,5 +239,7 @@ def convert_mac_addr(val):
        val - base64 encoded value (ex: '/c0gFyhb'))
        returns: a string formatted like a mac address (ex: 'fd:cd:20:17:28:5b')
     """
-    val_as_bytes = base64.b64decode(val)
-    return hexstr(val_as_bytes)
+    if not re.match("[0-9a-f]{2}([-:]?)[0-9a-f]{2}(\\1[0-9a-f]{2}){4}$", val):
+        val_as_bytes = base64.b64decode(val)
+        return hexstr(val_as_bytes)
+    return val