diff --git a/fitbitsync.py b/fitbitsync.py
index 187bd6c..74ab2d9 100644
--- a/fitbitsync.py
+++ b/fitbitsync.py
@@ -155,7 +155,7 @@ class ConfigManager:
             # Add padding if necessary for base64 decoding
             padding_needed = len(encoded_value) % 4
             if padding_needed != 0:
-                encoded_value += '=' * (4 - padding_needed)
+                encoded_value += b'=' * (4 - padding_needed)
 
             decoded_json_str = base64.b64decode(encoded_value).decode('utf-8')
             logger.debug(f"Consul decoded JSON string: {decoded_json_str}")