diff --git a/src/allmydata/frontends/sftpd.py b/src/allmydata/frontends/sftpd.py
index 3e5a55e98..aa15bbba7 100644
--- a/src/allmydata/frontends/sftpd.py
+++ b/src/allmydata/frontends/sftpd.py
@@ -314,8 +314,9 @@ class SFTPHandler:
         return d
 
     def _convert_sftp_path(self, pathstring):
+        assert pathstring[0] == "/"
         pathstring = pathstring.strip("/")
-        if pathstring == "" or  ".":
+        if pathstring == "":
             path = []
         else:
             path = pathstring.split("/")