diff --git a/Lib/reconvert.py b/Lib/reconvert.py
index 2c77ee91db5..64bab5b272c 100755
--- a/Lib/reconvert.py
+++ b/Lib/reconvert.py
@@ -166,7 +166,7 @@ def quote(s, quote=None):
         if q in s and altq not in s:
             q = altq
     else:
-        assert quote in ('"', "'")
+        assert quote in ('"', "'", '"""', "'''")
         q = quote
     res = q
     for c in s: