diff --git a/ipv8/community.py b/ipv8/community.py
index 0237ee39e..4c0dc507e 100644
--- a/ipv8/community.py
+++ b/ipv8/community.py
@@ -187,15 +187,19 @@ def add_message_handler(self, msg_num: int | type[Payload], callback: MessageHan
         actual_msg_num: int = 256
         if not isinstance(msg_num, int):
             if not hasattr(msg_num, "msg_id"):
-                raise RuntimeError(f"Attempted to add a handler for Payload {msg_num}, which does not specify a msg_id!")
+                msg = f"Attempted to add a handler for Payload {msg_num}, which does not specify a msg_id!"
+                raise RuntimeError(msg)
             actual_msg_num = cast(int, msg_num.msg_id)  # type: ignore[attr-defined]
         else:
             if msg_num < 0 or msg_num > 255:
-                raise RuntimeError(f"Attempted to add a handler for message number {msg_num}, which is not a byte!")
+                msg = f"Attempted to add a handler for message number {msg_num}, which is not a byte!"
+                raise RuntimeError(msg)
             actual_msg_num = msg_num
 
         if self.decode_map[actual_msg_num]:
-            raise RuntimeError(f"Attempted to add a handler for message number {actual_msg_num}, already mapped to {self.decode_map[actual_msg_num]}!")
+            msg = (f"Attempted to add a handler for message number {actual_msg_num}, "
+                   f"already mapped to {self.decode_map[actual_msg_num]}!")
+            raise RuntimeError(msg)
         self.decode_map[actual_msg_num] = callback
 
     def on_deprecated_message(self, source_address: Address, data: bytes) -> None: