diff --git a/src/pyramid_jwt/policy.py b/src/pyramid_jwt/policy.py
index 214d586..a7a2d1b 100644
--- a/src/pyramid_jwt/policy.py
+++ b/src/pyramid_jwt/policy.py
@@ -193,7 +193,7 @@ def __init__(
 
         if reissue_time and isinstance(reissue_time, datetime.timedelta):
             reissue_time = reissue_time.total_seconds()
-        self.reissue_time = reissue_time
+        self.reissue_time = int(reissue_time) if reissue_time is not None else None
 
         self.cookie_profile = CookieProfile(
             cookie_name=self.cookie_name,