diff --git a/src/ircmsgs.py b/src/ircmsgs.py
index 20533bbe5..4f3d5c6d5 100644
--- a/src/ircmsgs.py
+++ b/src/ircmsgs.py
@@ -81,8 +81,9 @@ class IrcMsg(object):
     # data.  Goodbye, __slots__.
     # On second thought, let's use methods for tagging.
     __slots__ = ('args', 'command', 'host', 'nick', 'prefix', 'user',
-                 '_hash', '_str', '_repr', '_len', 'tags')
-    def __init__(self, s='', command='', args=(), prefix='', msg=None):
+                 '_hash', '_str', '_repr', '_len', 'tags', 'reply_env')
+    def __init__(self, s='', command='', args=(), prefix='', msg=None,
+            reply_env=None):
         assert not (msg and s), 'IrcMsg.__init__ cannot accept both s and msg'
         if not s and not command and not msg:
             raise MalformedIrcMsg('IRC messages require a command.')
@@ -90,6 +91,7 @@ class IrcMsg(object):
         self._repr = None
         self._hash = None
         self._len = None
+        self.reply_env = reply_env
         self.tags = {}
         if s:
             originalString = s
diff --git a/src/ircutils.py b/src/ircutils.py
index 9c293e4dc..7f552e00e 100644
--- a/src/ircutils.py
+++ b/src/ircutils.py
@@ -713,6 +713,8 @@ def standardSubstitute(irc, msg, text, env=None):
         's': localtime[5], 'sec': localtime[5], 'second': localtime[5],
         'tz': time.strftime('%Z', localtime),
         })
+    if msg.reply_env:
+        vars.update(msg.reply_env)
     if env is not None:
         vars.update(env)
     t = string.Template(text)