diff --git a/Lib/telnetlib.py b/Lib/telnetlib.py
index f073050b817..8a2513b4ef4 100644
--- a/Lib/telnetlib.py
+++ b/Lib/telnetlib.py
@@ -1,4 +1,4 @@
-"""TELNET client class.
+r"""TELNET client class.
 
 Based on RFC 854: TELNET Protocol Specification, by J. Postel and
 J. Reynolds