diff --git a/copyparty/broker_mpw.py b/copyparty/broker_mpw.py
index ae4b9fe5..fdfbbe43 100644
--- a/copyparty/broker_mpw.py
+++ b/copyparty/broker_mpw.py
@@ -35,7 +35,7 @@ class MpWorker(object):
             signal.signal(signal.SIGINT, self.signal_handler)
 
         # instantiate all services here (TODO: inheritance?)
-        self.httpsrv = HttpSrv(self)
+        self.httpsrv = HttpSrv(self, True)
         self.httpsrv.disconnect_func = self.httpdrop
 
         # on winxp and some other platforms,
@@ -75,7 +75,7 @@ class MpWorker(object):
 
                 if self.args.log_conn:
                     self.log("%s %s" % addr, "|%sC-qpop" % ("-" * 4,), c="1;30")
-                
+
                 self.httpsrv.accept(sck, addr)
 
                 with self.mutex:
diff --git a/copyparty/httpconn.py b/copyparty/httpconn.py
index b505f2dd..cb2162dd 100644
--- a/copyparty/httpconn.py
+++ b/copyparty/httpconn.py
@@ -35,6 +35,7 @@ class HttpConn(object):
 
         self.args = hsrv.args
         self.auth = hsrv.auth
+        self.is_mp = hsrv.is_mp
         self.cert_path = hsrv.cert_path
 
         enth = HAVE_PIL and not self.args.no_thumb
@@ -174,6 +175,11 @@ class HttpConn(object):
             self.sr = Unrecv(self.s)
 
         while True:
+            if self.is_mp:
+                self.workload += 50
+                if self.workload >= 2 ** 31:
+                    self.workload = 100
+
             cli = HttpCli(self)
             if not cli.run():
                 return
diff --git a/copyparty/httpsrv.py b/copyparty/httpsrv.py
index 996bd90d..356d9c58 100644
--- a/copyparty/httpsrv.py
+++ b/copyparty/httpsrv.py
@@ -35,8 +35,9 @@ class HttpSrv(object):
     relying on MpSrv for performance (HttpSrv is just plain threads)
     """
 
-    def __init__(self, broker):
+    def __init__(self, broker, is_mp=False):
         self.broker = broker
+        self.is_mp = is_mp
         self.args = broker.args
         self.log = broker.log
 
@@ -84,13 +85,14 @@ class HttpSrv(object):
         cli = HttpConn(sck, addr, self)
         with self.mutex:
             self.clients[cli] = 0
-            self.workload += 50
 
-            if not self.workload_thr_alive:
-                self.workload_thr_alive = True
-                thr = threading.Thread(target=self.thr_workload)
-                thr.daemon = True
-                thr.start()
+            if self.is_mp:
+                self.workload += 50
+                if not self.workload_thr_alive:
+                    self.workload_thr_alive = True
+                    thr = threading.Thread(target=self.thr_workload)
+                    thr.daemon = True
+                    thr.start()
 
         try:
             if self.args.log_conn:
diff --git a/copyparty/util.py b/copyparty/util.py
index 5b627f9b..17b91203 100644
--- a/copyparty/util.py
+++ b/copyparty/util.py
@@ -852,13 +852,14 @@ def yieldfile(fn):
 
 
 def hashcopy(actor, fin, fout):
-    u32_lim = int((2 ** 31) * 0.9)
+    is_mp = actor.is_mp
     hashobj = hashlib.sha512()
     tlen = 0
     for buf in fin:
-        actor.workload += 1
-        if actor.workload > u32_lim:
-            actor.workload = 100  # prevent overflow
+        if is_mp:
+            actor.workload += 1
+            if actor.workload > 2 ** 31:
+                actor.workload = 100  # prevent overflow
 
         tlen += len(buf)
         hashobj.update(buf)
diff --git a/tests/util.py b/tests/util.py
index 1a24ac2e..eb412008 100644
--- a/tests/util.py
+++ b/tests/util.py
@@ -116,6 +116,7 @@ class VHttpConn(object):
         self.addr = ("127.0.0.1", "42069")
         self.args = args
         self.auth = auth
+        self.is_mp = False
         self.log_func = log
         self.log_src = "a"
         self.lf_url = None