diff --git a/synapse/types.py b/synapse/types.py
index 7cb24cecb2354e2a9086d7f7eb71908259ee032f..cc7c182a78f476ec8a038ea7f9e28d230c67963c 100644
--- a/synapse/types.py
+++ b/synapse/types.py
@@ -169,7 +169,7 @@ class DomainSpecificString(
         except Exception:
             return False
 
-    __str__ = to_string
+    __repr__ = to_string
 
 
 class UserID(DomainSpecificString):