diff --git a/copyparty/up2k.py b/copyparty/up2k.py
index 3001e60b..eb1c1357 100644
--- a/copyparty/up2k.py
+++ b/copyparty/up2k.py
@@ -145,9 +145,12 @@ class Up2k(object):
         self.entags: dict[str, set[str]] = {}
         self.mtp_parsers: dict[str, dict[str, MParser]] = {}
         self.pending_tags: list[tuple[set[str], str, str, dict[str, Any]]] = []
-        self.hashq: Queue[tuple[str, str, str, str, str, float, str, bool]] = Queue()
+        self.hashq: Queue[
+            tuple[str, str, dict[str, Any], str, str, str, float, str, bool]
+        ] = Queue()
         self.tagq: Queue[tuple[str, str, str, str, str, float]] = Queue()
         self.tag_event = threading.Condition()
+        self.hashq_mutex = threading.Lock()
         self.n_hashq = 0
         self.n_tagq = 0
         self.mpool_used = False
@@ -2351,7 +2354,8 @@ class Up2k(object):
                 t = "cannot receive uploads right now;\nserver busy with {}.\nPlease wait; the client will retry..."
                 raise Pebkac(503, t.format(self.blocked or "[unknown]"))
         except TypeError:
-            # py2
+            if not PY2:
+                raise
             with self.mutex:
                 self._job_volchk(cj)
 
@@ -3991,16 +3995,16 @@ class Up2k(object):
             self.log("tagged {} ({}+{})".format(abspath, ntags1, len(tags) - ntags1))
 
     def _hasher(self) -> None:
-        with self.mutex:
+        with self.hashq_mutex:
             self.n_hashq += 1
 
         while True:
-            with self.mutex:
+            with self.hashq_mutex:
                 self.n_hashq -= 1
             # self.log("hashq {}".format(self.n_hashq))
 
             task = self.hashq.get()
-            if len(task) != 8:
+            if len(task) != 9:
                 raise Exception("invalid hash task")
 
             try:
@@ -4009,11 +4013,14 @@ class Up2k(object):
             except Exception as ex:
                 self.log("failed to hash %s: %s" % (task, ex), 1)
 
-    def _hash_t(self, task: tuple[str, str, str, str, str, float, str, bool]) -> bool:
-        ptop, vtop, rd, fn, ip, at, usr, skip_xau = task
+    def _hash_t(
+        self, task: tuple[str, str, dict[str, Any], str, str, str, float, str, bool]
+    ) -> bool:
+        ptop, vtop, flags, rd, fn, ip, at, usr, skip_xau = task
         # self.log("hashq {} pop {}/{}/{}".format(self.n_hashq, ptop, rd, fn))
-        if "e2d" not in self.flags[ptop]:
-            return True
+        with self.mutex:
+            if not self.register_vpath(ptop, flags):
+                return True
 
         abspath = djoin(ptop, rd, fn)
         self.log("hashing " + abspath)
@@ -4064,11 +4071,22 @@ class Up2k(object):
         usr: str,
         skip_xau: bool = False,
     ) -> None:
-        with self.mutex:
-            self.register_vpath(ptop, flags)
-            self.hashq.put((ptop, vtop, rd, fn, ip, at, usr, skip_xau))
+        if "e2d" not in flags:
+            return
+
+        if self.n_hashq > 1024:
+            t = "%d files in hashq; taking a nap"
+            self.log(t % (self.n_hashq,), 6)
+
+            for _ in range(self.n_hashq // 1024):
+                time.sleep(0.1)
+                if self.n_hashq < 1024:
+                    break
+
+        zt = (ptop, vtop, flags, rd, fn, ip, at, usr, skip_xau)
+        with self.hashq_mutex:
+            self.hashq.put(zt)
             self.n_hashq += 1
-        # self.log("hashq {} push {}/{}/{}".format(self.n_hashq, ptop, rd, fn))
 
     def shutdown(self) -> None:
         self.stop = True