diff --git a/contrib/check-code.py b/contrib/check-code.py
--- a/contrib/check-code.py
+++ b/contrib/check-code.py
@@ -414,7 +414,7 @@
 
 txtpats = [
   [
-    ('\s$', 'trailing whitespace'),
+    (r'\s$', 'trailing whitespace'),
     ('.. note::[ \n][^\n]', 'add two newlines after note::')
   ],
   []