diff --git a/Lib/imaplib.py b/Lib/imaplib.py
index a63ba8d..2d1db79 100644
--- a/Lib/imaplib.py
+++ b/Lib/imaplib.py
@@ -1211,11 +1211,9 @@ class IMAP4:
 
         def _dump_ur(self, dict):
             # Dump untagged responses (in `dict').
-            l = dict.items()
-            if not l: return
-            t = '\n\t\t'
-            l = map(lambda x:'%s: "%s"' % (x[0], x[1][0] and '" "'.join(x[1]) or ''), l)
-            self._mesg('untagged responses dump:%s%s' % (t, t.join(l)))
+            if dict:
+                self._mesg('untagged responses dump:' +
+                    ''.join('\n\t\t%s: %r' % (x[0], x[1]) for x in dict.items()))
 
         def _log(self, line):
             # Keep log of last `_cmd_log_len' interactions for debugging.