diff --git a/copyparty/httpcli.py b/copyparty/httpcli.py
index 189f18a0..23727495 100644
--- a/copyparty/httpcli.py
+++ b/copyparty/httpcli.py
@@ -1658,6 +1658,8 @@ class HttpCli(object):
                     "expires": time.time() + self.args.wopi_ttl,
                 }
 
+        assert atoken and session  # type: ignore  # !rm
+
         xml = url = "?"
         try:
             from .dxml import parse_xml
diff --git a/copyparty/util.py b/copyparty/util.py
index fccafa49..aeca5ae1 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -352,7 +352,7 @@ RE_MEMAVAIL = re.compile("^MemAvailable:.* kB")
 
 if PY2:
 
-    def umktrans(s1, s2):
+    def umktrans(s1: str, s2: str):
         return {ord(c1): ord(c2) for c1, c2 in zip(s1, s2)}
 
 else: