diff --git a/discord/message.py b/discord/message.py
index fc5dde9d4..7c809d9f6 100644
--- a/discord/message.py
+++ b/discord/message.py
@@ -218,7 +218,7 @@ class Message:
     def _handle_mention_roles(self, role_mentions):
         self.role_mentions = []
         if self.guild is not None:
-            for role_id in role_mentions:
+            for role_id in map(int, role_mentions):
                 role = utils.get(self.guild.roles, id=role_id)
                 if role is not None:
                     self.role_mentions.append(role)