diff --git a/copyparty/__version__.py b/copyparty/__version__.py
index c28b2f16..2d46a7e2 100644
--- a/copyparty/__version__.py
+++ b/copyparty/__version__.py
@@ -1,6 +1,6 @@
 # coding: utf-8
 
-VERSION = (0, 11, 10)
+VERSION = (0, 11, 11)
 CODENAME = "the grid"
 BUILD_DT = (2021, 6, 8)
 
diff --git a/copyparty/httpcli.py b/copyparty/httpcli.py
index a5112595..a9187eef 100644
--- a/copyparty/httpcli.py
+++ b/copyparty/httpcli.py
@@ -994,6 +994,8 @@ class HttpCli(object):
         cli_lastmod = self.headers.get("if-modified-since")
         if cli_lastmod:
             try:
+                # some browser append "; length=573"
+                cli_lastmod = cli_lastmod.split(";")[0].strip()
                 cli_dt = time.strptime(cli_lastmod, HTTP_TS_FMT)
                 cli_ts = calendar.timegm(cli_dt)
                 return file_lastmod, int(file_ts) > int(cli_ts)