diff --git a/waybackpy/wrapper.py b/waybackpy/wrapper.py
index d305960..6d14e66 100644
--- a/waybackpy/wrapper.py
+++ b/waybackpy/wrapper.py
@@ -317,7 +317,7 @@ class Url:
         if not user_agent:
             user_agent = self.user_agent
 
-        headers = {"User-Agent": self.user_agent}
+        headers = {"User-Agent": str(user_agent)}
         response = _get_response(url, params=None, headers=headers)
 
         if not encoding: