diff --git a/tools/patman/gitutil.py b/tools/patman/gitutil.py
index fb9e67c..dce7fa2 100644
--- a/tools/patman/gitutil.py
+++ b/tools/patman/gitutil.py
@@ -412,9 +412,7 @@
     if smtp_server:
         cmd.append('--smtp-server=%s' % smtp_server)
     if in_reply_to:
-        if type(in_reply_to) != str:
-            in_reply_to = in_reply_to.encode('utf-8')
-        cmd.append('--in-reply-to="%s"' % in_reply_to)
+        cmd.append('--in-reply-to="%s"' % tools.FromUnicode(in_reply_to))
     if thread:
         cmd.append('--thread')