diff --git a/bot/bot.py b/bot/bot.py
index 9d4e5b8..3c50e10 100644
--- a/bot/bot.py
+++ b/bot/bot.py
@@ -62,7 +62,7 @@ def extract_amazon_url_with_referer(text: str):
             product_code = product_code_regex_result.group(0)
         if vendor_and_smid_result:
             extra_params = (''.join(str(w) for w in vendor_and_smid_result if w is not None))
-            extra_params.replace('?','&')
+            extra_params = extra_params.replace('?','&')
             
         return helpers.new_refer_url(product_code, extra_params)