diff --git a/copyparty/broker_util.py b/copyparty/broker_util.py
index 3406dc91..527ecc7b 100644
--- a/copyparty/broker_util.py
+++ b/copyparty/broker_util.py
@@ -4,7 +4,6 @@ from __future__ import print_function, unicode_literals
 
 import traceback
 
-from .__init__ import PY2
 from .util import Pebkac, Queue
 
 
diff --git a/copyparty/httpcli.py b/copyparty/httpcli.py
index ae443063..0de326c3 100644
--- a/copyparty/httpcli.py
+++ b/copyparty/httpcli.py
@@ -420,9 +420,11 @@ class HttpCli(object):
         vfs, rem = self.conn.auth.vfs.get(self.vpath, self.uname, False, True)
         self._assert_safe_rem(rem)
 
+        sanitized = sanitize_fn(new_dir)
+
         if not nullwrite:
             fdir = os.path.join(vfs.realpath, rem)
-            fn = os.path.join(fdir, sanitize_fn(new_dir))
+            fn = os.path.join(fdir, sanitized)
 
             if not os.path.isdir(fsenc(fdir)):
                 raise Pebkac(500, "parent folder does not exist")
@@ -435,7 +437,7 @@ class HttpCli(object):
             except:
                 raise Pebkac(500, "mkdir failed, check the logs")
 
-        vpath = "{}/{}".format(self.vpath, new_dir).lstrip("/")
+        vpath = "{}/{}".format(self.vpath, sanitized).lstrip("/")
         html = self.conn.tpl_msg.render(
             h2='<a href="/{}">go to /{}</a>'.format(
                 quotep(vpath), html_escape(vpath, quote=False)
@@ -457,9 +459,11 @@ class HttpCli(object):
         if not new_file.endswith(".md"):
             new_file += ".md"
 
+        sanitized = sanitize_fn(new_file)
+
         if not nullwrite:
             fdir = os.path.join(vfs.realpath, rem)
-            fn = os.path.join(fdir, sanitize_fn(new_file))
+            fn = os.path.join(fdir, sanitized)
 
             if os.path.exists(fsenc(fn)):
                 raise Pebkac(500, "that file exists already")
@@ -467,7 +471,7 @@ class HttpCli(object):
             with open(fsenc(fn), "wb") as f:
                 f.write(b"`GRUNNUR`\n")
 
-        vpath = "{}/{}".format(self.vpath, new_file).lstrip("/")
+        vpath = "{}/{}".format(self.vpath, sanitized).lstrip("/")
         html = self.conn.tpl_msg.render(
             h2='<a href="/{}?edit">go to /{}?edit</a>'.format(
                 quotep(vpath), html_escape(vpath, quote=False)
diff --git a/copyparty/tcpsrv.py b/copyparty/tcpsrv.py
index 035559fd..5c6c0e69 100644
--- a/copyparty/tcpsrv.py
+++ b/copyparty/tcpsrv.py
@@ -24,7 +24,7 @@ class TcpSrv(object):
         ip = "127.0.0.1"
         eps = {ip: "local only"}
         if self.args.i != ip:
-            eps = self.detect_interfaces(self.args.i) or eps
+            eps = self.detect_interfaces(self.args.i) or {self.args.i: "external"}
 
         for ip, desc in sorted(eps.items(), key=lambda x: x[1]):
             self.log(
diff --git a/copyparty/up2k.py b/copyparty/up2k.py
index 4c8ac4fe..b3dc1271 100644
--- a/copyparty/up2k.py
+++ b/copyparty/up2k.py
@@ -13,7 +13,7 @@ import threading
 from copy import deepcopy
 
 from .__init__ import WINDOWS
-from .util import Pebkac, Queue, fsenc
+from .util import Pebkac, Queue, fsenc, sanitize_fn
 
 
 class Up2k(object):
@@ -48,6 +48,7 @@ class Up2k(object):
         self.r_hash = re.compile("^[0-9a-zA-Z_-]{43}$")
 
     def handle_json(self, cj):
+        cj["name"] = sanitize_fn(cj["name"])
         wark = self._get_wark(cj)
         now = time.time()
         with self.mutex:
diff --git a/copyparty/util.py b/copyparty/util.py
index 54ad6a21..854f5b8e 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -356,7 +356,30 @@ def undot(path):
 
 
 def sanitize_fn(fn):
-    return fn.replace("\\", "/").split("/")[-1].strip()
+    fn = fn.replace("\\", "/").split("/")[-1]
+
+    if WINDOWS:
+        for bad, good in [
+            ["<", "＜"],
+            [">", "＞"],
+            [":", "："],
+            ['"', "＂"],
+            ["/", "／"],
+            ["\\", "＼"],
+            ["|", "｜"],
+            ["?", "？"],
+            ["*", "＊"],
+        ]:
+            fn = fn.replace(bad, good)
+
+        bad = ["con", "prn", "aux", "nul"]
+        for n in range(1, 10):
+            bad += "com{0} lpt{0}".format(n).split(" ")
+
+        if fn.lower() in bad:
+            fn = "_" + fn
+
+    return fn.strip()
 
 
 def exclude_dotfiles(filepaths):