diff --git a/Lib/test/test_property.py b/Lib/test/test_property.py
index 7d1c4a1e128..d91ad1c1912 100644
--- a/Lib/test/test_property.py
+++ b/Lib/test/test_property.py
@@ -342,7 +342,7 @@ class cls:
 
 
 class PropertyUnreachableAttributeNoName(_PropertyUnreachableAttribute, unittest.TestCase):
-    msg_format = "^property of 'PropertyUnreachableAttributeNoName\.cls' object {}$"
+    msg_format = r"^property of 'PropertyUnreachableAttributeNoName\.cls' object {}$"
 
     class cls:
         pass