diff --git a/Makefile b/Makefile
index bbb7277..7c0b584 100644
--- a/Makefile
+++ b/Makefile
@@ -50,13 +50,13 @@ test: certs
 	$(LUA) $(DELIM) $(PKGPATH) tests/largetransfer.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/lock.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/loop_starter.lua
+	$(LUA) $(DELIM) $(PKGPATH) tests/pause.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/queue.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/removeserver.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/removethread.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/request.lua 'http://www.google.com'
 	$(LUA) $(DELIM) $(PKGPATH) tests/request.lua 'https://www.google.nl' true
 	$(LUA) $(DELIM) $(PKGPATH) tests/semaphore.lua
-	$(LUA) $(DELIM) $(PKGPATH) tests/sleep.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/starve.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/tcptimeout.lua
 	$(LUA) $(DELIM) $(PKGPATH) tests/timer.lua
diff --git a/docs/index.html b/docs/index.html
index 092dbaa..d5fd87a 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -105,6 +105,8 @@ <h2><a name="history"></a>History</h2>
         <li>Fix: an error in the timer callback would kill the timer.</li>
         <li>Added: <code>copas.geterrorhandler</code> to retrieve the active errorhandler.</li>
         <li>Added: option <code>errorhandler</code> for timer objects.</li>
+        <li>Added: <code>copas.pause</code> and <code>copas.pauseforever</code> to replace <code>copas.sleep</code>. The latter
+        method can accidentally sleep-forever if time arithmetic returns a negative result.</li>
         <li>Change: renamed <code>copas.setErrorHandler</code> to <code>copas.seterrorhandler</code>.</li>
         <li>Change: renamed <code>copas.useSocketTimeoutErrors</code> to <code>copas.usesockettimeouterrors</code>.</li>
     </ul></dd>
diff --git a/docs/manual.html b/docs/manual.html
index 9cd1c51..76f28a7 100644
--- a/docs/manual.html
+++ b/docs/manual.html
@@ -381,7 +381,7 @@ <h2><a name="synchronization"></a>Synchronization primitives</h2>
   end
 
   print("doing something on my own")
-  copas.sleep()  -- allow to yield, while inside the lock
+  copas.pause()  -- allow to yield, while inside the lock
   print("after " .. ok .. " seconds waiting")
 
   lock:release()
diff --git a/docs/reference.html b/docs/reference.html
index 7176151..d31e35c 100644
--- a/docs/reference.html
+++ b/docs/reference.html
@@ -298,14 +298,23 @@ <h3>Non-blocking data exchange and timer/sleep functions</h3>
 exchange data with other services.</p>
 
 <dl class="reference">
+    <dt><strong><code>copas.pause([delay])</code></strong></dt>
+    <dd>Pauses the current co-routine. Parameter <code>delay</code> (in seconds) is optional
+    and defaults to 0. If <code>delay &lt= 0</code> then it will pause for 0 seconds.
+    </dd>
+
+    <dt><strong><code>copas.pauseforever()</code></strong></dt>
+    <dd>Pauses the current co-routine until explicitly woken by a call to
+    <code>copas.wakeup()</code>.
+    </dd>
+
     <dt><strong><code>copas.sleep([sleeptime])</code></strong></dt>
-    <dd>Pauses the current co-routine. Parameter <code>sleeptime</code> (in seconds) is optional
-    and defaults to 0. If <code>sleeptime &lt 0</code>
-    then it will sleep until explicitly woken by a call to <code>copas.wakeup()</code>.
+    <dd><i>Deprecated:</i> use <code>copas.pause</code> and <code>copas.pauseforever</code>
+    instead.
     </dd>
 
     <dt><strong><code>copas.wakeup(co)</code></strong></dt>
-    <dd><code>co</code> is the coroutine to wakeup, see <code>copas.sleep()</code>.
+    <dd><code>co</code> is the coroutine to wakeup, see <code>copas.pauseforever()</code>.
     </dd>
 
     <dt><strong><code>sock:close()</code></strong></dt>
diff --git a/src/copas.lua b/src/copas.lua
index ced7c1d..24f2b67 100644
--- a/src/copas.lua
+++ b/src/copas.lua
@@ -497,7 +497,7 @@ function copas.receive(client, pattern, part)
 
     -- guarantees that high throughput doesn't take other threads to starvation
     if (math.random(100) > 90) then
-      copas.sleep(0)
+      copas.pause()
     end
 
     if s then
@@ -541,7 +541,7 @@ function copas.receivefrom(client, size)
 
     -- garantees that high throughput doesn't take other threads to starvation
     if (math.random(100) > 90) then
-      copas.sleep(0)
+      copas.pause()
     end
 
     if s then
@@ -578,7 +578,7 @@ function copas.receivepartial(client, pattern, part)
 
     -- guarantees that high throughput doesn't take other threads to starvation
     if (math.random(100) > 90) then
-      copas.sleep(0)
+      copas.pause()
     end
 
     if s or (type(part) == "string" and #part > orig_size) then
@@ -626,7 +626,7 @@ function copas.send(client, data, from, to)
 
     -- guarantees that high throughput doesn't take other threads to starvation
     if (math.random(100) > 90) then
-      copas.sleep(0)
+      copas.pause()
     end
 
     if s then
@@ -1198,7 +1198,7 @@ function copas.addnamedthread(name, handler, ...)
   -- create a coroutine that skips the first argument, which is always the socket
   -- passed by the scheduler, but `nil` in case of a task/thread
   local thread = coroutine_create(function(_, ...)
-    copas.sleep(0)
+    copas.pause()
     return handler(...)
   end)
   if name then
@@ -1230,10 +1230,29 @@ end
 
 -- yields the current coroutine and wakes it after 'sleeptime' seconds.
 -- If sleeptime < 0 then it sleeps until explicitly woken up using 'wakeup'
+-- TODO: deprecated, remove in next major
 function copas.sleep(sleeptime)
   coroutine_yield((sleeptime or 0), _sleeping)
 end
 
+
+-- yields the current coroutine and wakes it after 'sleeptime' seconds.
+-- if sleeptime < 0 then it sleeps 0 seconds.
+function copas.pause(sleeptime)
+  if sleeptime and sleeptime > 0 then
+    coroutine_yield(sleeptime, _sleeping)
+  else
+    coroutine_yield(0, _sleeping)
+  end
+end
+
+
+-- yields the current coroutine until explicitly woken up using 'wakeup'
+function copas.pauseforever()
+  coroutine_yield(-1, _sleeping)
+end
+
+
 -- Wakes up a sleeping coroutine 'co'.
 function copas.wakeup(co)
   _sleeping:wakeup(co)
@@ -1258,7 +1277,7 @@ do
 
   time_out_thread = copas.addnamedthread("copas_core_timer", function()
     while true do
-      copas.sleep(TIMEOUT_PRECISION)
+      copas.pause(TIMEOUT_PRECISION)
       timerwheel:step()
     end
   end)
@@ -1358,7 +1377,7 @@ local _sleeping_task = {} do
     local co = _sleeping:pop(now)
     while co do
       -- we're pushing them to _resumable, since that list will be replaced before
-      -- executing. This prevents tasks running twice in a row with sleep(0) for example.
+      -- executing. This prevents tasks running twice in a row with pause(0) for example.
       -- So here we won't execute, but at _resumable step which is next
       _resumable:push(co)
       co = _sleeping:pop(now)
diff --git a/src/copas/lock.lua b/src/copas/lock.lua
index b16a03d..3a8dadd 100644
--- a/src/copas/lock.lua
+++ b/src/copas/lock.lua
@@ -124,7 +124,7 @@ function lock:get(timeout)
     copas.timeout(timeout, timeout_handler)
 
     start_time = gettime()
-    copas.sleep(-1)
+    copas.pauseforever()
 
     local err = self.errors[co]
     self.errors[co] = nil
diff --git a/src/copas/semaphore.lua b/src/copas/semaphore.lua
index f88d3d0..db7eaa3 100644
--- a/src/copas/semaphore.lua
+++ b/src/copas/semaphore.lua
@@ -160,7 +160,7 @@ function semaphore:take(requested, timeout)
   }
   self.q_tail = self.q_tail + 1
 
-  copas.sleep(-1) -- block until woken
+  copas.pauseforever() -- block until woken
   if self.to_flags[co] then
     -- a timeout happened
     self.to_flags[co] = nil
diff --git a/src/copas/timer.lua b/src/copas/timer.lua
index 91c5b84..ba96711 100644
--- a/src/copas/timer.lua
+++ b/src/copas/timer.lua
@@ -28,7 +28,7 @@ do
     if self.errorhandler then
       copas.seterrorhandler(self.errorhandler)
     end
-    copas.sleep(initial_delay)
+    copas.pause(initial_delay)
     while true do
       if not self.cancelled then
         if not self.recurring then
@@ -52,7 +52,7 @@ do
         return
       end
 
-      copas.sleep(self.delay)
+      copas.pause(self.delay)
     end
   end
 
diff --git a/tests/close.lua b/tests/close.lua
index c26d406..cbc31b3 100644
--- a/tests/close.lua
+++ b/tests/close.lua
@@ -34,13 +34,13 @@ copas.loop(function()
     copas.addserver(server, copas.handler(function(conn_skt)
       -- client connected, we're not doing anything, let the client
       -- wait in the read/write queues
-      copas.sleep(2)
+      copas.pause(2)
       -- now we're closing the connecting_socket
       close_time = socket.gettime()
       print("closing client socket now, client receive and send operation should immediately error out now")
       client_socket:close()
 
-      copas.sleep(10)
+      copas.pause(10)
       conn_skt:close()
       copas.removeserver(server)
       print "timeout, test failed"
diff --git a/tests/errhandlers.lua b/tests/errhandlers.lua
index 25755d0..cc5de10 100644
--- a/tests/errhandlers.lua
+++ b/tests/errhandlers.lua
@@ -63,7 +63,7 @@ if _VERSION ~= "Lua 5.1" then
           end
           f()
       end)
-      copas.sleep(1)
+      copas.pause(1)
     end)
 
     print = old_print   --luacheck: ignore
@@ -83,7 +83,7 @@ tests.yielding_from_user_code_fails = function()
   end
 
   copas.loop(function()
-    copas.sleep(1)
+    copas.pause(1)
     coroutine.yield() -- directly yield to Copas
   end)
 
@@ -137,7 +137,7 @@ tests.timerwheel_callbacks_call_the_default_error_handler = function()
   copas.setErrorHandler(function() call_count = call_count - 10 end, true)
   copas.loop(function()
     copas.timeout(0.01, function(co) error("hi there!") end)
-    copas.sleep(1)
+    copas.pause(1)
   end)
 
   assert(call_count == -10, "expected callcount -10, got: " .. tostring(call_count))
diff --git a/tests/exit.lua b/tests/exit.lua
index 53ed54e..ecf7321 100644
--- a/tests/exit.lua
+++ b/tests/exit.lua
@@ -7,7 +7,7 @@ local done = false
 
 copas.addthread(function()
   for i = 1, 5 do
-    copas.sleep(0)
+    copas.pause()
     print(i)
   end
 
@@ -43,7 +43,7 @@ copas.addserver(server, function(skt)
 end)
 
 copas.addthread(function()
-  copas.sleep(1)
+  copas.pause(1)
   local skt = socket.connect("localhost", 20000)
   print("Sending "..message.."\\n")
   local bytes = copas.send(skt, message.."\n")
diff --git a/tests/exittest.lua b/tests/exittest.lua
index 20ebae5..5d4ad67 100644
--- a/tests/exittest.lua
+++ b/tests/exittest.lua
@@ -19,8 +19,8 @@ print("1) success")
 
 print("2) Testing exiting when a task finishes within the loop")
 copas.addthread(function()
-  copas.sleep(0.1) -- wait until loop is running
-  copas.sleep(0.1) -- wait again to make sure its not the initial step in the loop
+  copas.pause(0.1) -- wait until loop is running
+  copas.pause(0.1) -- wait again to make sure its not the initial step in the loop
   print("","2 running...")
   testran = 2
 end)
@@ -40,8 +40,8 @@ print("3) success")
 
 print("4) Testing exiting when a task fails in the loop")
 copas.addthread(function()
-  copas.sleep(0.1) -- wait until loop is running
-  copas.sleep(0.1) -- wait again to make sure its not the initial step in the loop
+  copas.pause(0.1) -- wait until loop is running
+  copas.pause(0.1) -- wait again to make sure its not the initial step in the loop
   print("","4 running...")
   testran = 4
   error("error on purpose")
@@ -54,7 +54,7 @@ print("5) Testing exiting when a task permanently sleeps before the loop")
 copas.addthread(function()
   print("","5 running...")
   testran = 5
-  copas.sleep(-1) -- sleep until explicitly woken up
+  copas.pauseforever() -- sleep until explicitly woken up
 end)
 copas.loop()
 assert(testran == 5, "Test 5 was not executed!")
@@ -62,11 +62,11 @@ print("5) success")
 
 print("6) Testing exiting when a task permanently sleeps in the loop")
 copas.addthread(function()
-  copas.sleep(0.1) -- wait until loop is running
-  copas.sleep(0.1) -- wait again to make sure its not the initial step in the loop
+  copas.pause(0.1) -- wait until loop is running
+  copas.pause(0.1) -- wait again to make sure its not the initial step in the loop
   print("","6 running...")
   testran = 6
-  copas.sleep(-1) -- sleep until explicitly woken up
+  copas.pauseforever() -- sleep until explicitly woken up
 end)
 copas.loop()
 assert(testran == 6, "Test 6 was not executed!")
diff --git a/tests/http-timeout.lua b/tests/http-timeout.lua
index ecfab48..48be63a 100644
--- a/tests/http-timeout.lua
+++ b/tests/http-timeout.lua
@@ -64,7 +64,7 @@ local function runtest()
         os.exit(1)
       end
       -- we timeout on the request, so sleep here and exit
-      copas.sleep(timeout + 1) -- sleep 1 second more than the requester timeout, to force a timeout on the request
+      copas.pause(timeout + 1) -- sleep 1 second more than the requester timeout, to force a timeout on the request
       print("Server reading port 49500: request-timeout complete")
       return skt:close()
     end
@@ -105,7 +105,7 @@ local function runtest()
       os.exit(1)
     end
 
-    copas.sleep(timeout + 1) -- sleep 1 second more than the requester timeout, to force a timeout on the response
+    copas.pause(timeout + 1) -- sleep 1 second more than the requester timeout, to force a timeout on the response
     print("Server reading port 49500: response-timeout complete")
     return skt:close()
   end))
@@ -115,7 +115,7 @@ local function runtest()
   copas.addnamedthread("test request", function()
 
     print "Waiting a bit for server to start..."
-    copas.sleep(1) -- give server some time to start
+    copas.pause(1) -- give server some time to start
 
     do
       print("first test: succesfull round trip")
@@ -152,7 +152,7 @@ local function runtest()
 
       -- cleanup; sleep 2 secs to wait for closing server socket
       -- to ensure any error messages do not get intermixed with the next tests output
-      copas.sleep(2)
+      copas.pause(2)
       print(("="):rep(80))
     end
 
@@ -192,7 +192,7 @@ local function runtest()
 
       -- cleanup; sleep 2 secs to wait for closing server socket
       -- to ensure any error messages do not get intermixed with the next tests output
-      copas.sleep(2)
+      copas.pause(2)
       print(("="):rep(80))
     end
 
@@ -232,7 +232,7 @@ local function runtest()
 
       -- cleanup; sleep 2 secs to wait for closing server socket
       -- to ensure any error messages do not get intermixed with the next tests output
-      copas.sleep(2)
+      copas.pause(2)
       print(("="):rep(80))
     end
 
@@ -272,7 +272,7 @@ local function runtest()
 
       -- cleanup; sleep 2 secs to wait for closing server socket
       -- to ensure any error messages do not get intermixed with the next tests output
-      copas.sleep(2)
+      copas.pause(2)
       print(("="):rep(80))
     end
 
@@ -312,7 +312,7 @@ local function runtest()
 
       -- cleanup; sleep 2 secs to wait for closing server socket
       -- to ensure any error messages do not get intermixed with the next tests output
-      copas.sleep(2)
+      copas.pause(2)
       print(("="):rep(80))
     end
 
diff --git a/tests/largetransfer.lua b/tests/largetransfer.lua
index 02987e2..21045a9 100644
--- a/tests/largetransfer.lua
+++ b/tests/largetransfer.lua
@@ -76,7 +76,7 @@ local function runtest()
   copas.addnamedthread("test timeout thread", function()
       local i = 1
       while done ~= 4 do
-        copas.sleep(1)
+        copas.pause(1)
         print(i, "seconds:", socket.gettime()-start)
         i = i + 1
         if i > 60 then
diff --git a/tests/lock.lua b/tests/lock.lua
index cd170c5..6e167cd 100644
--- a/tests/lock.lua
+++ b/tests/lock.lua
@@ -54,7 +54,7 @@ copas.loop(function()
         --print(i, "got it!")
         success_count = success_count + 1
         if i == size/3 then
-          copas.sleep(3) -- keep it long enough for the next 500 to timeout
+          copas.pause(3) -- keep it long enough for the next 500 to timeout
           --print(i, "releasing ")
           assert(lock1:release()) -- by now the 2nd 500 timed out
           --print(i, "destroying ")
@@ -69,7 +69,7 @@ copas.loop(function()
         --print(i, "timed out!")
         timeout_count = timeout_count + 1
         --if i == (size*2)/3 then
-        --  copas.sleep(2) -- to ensure thread 500 finished its sleep above
+        --  copas.pause(2) -- to ensure thread 500 finished its sleep above
         --end
         tracker[i] = nil
 
@@ -88,7 +88,7 @@ copas.loop(function()
   print("releasing "..size.." threads...", gettime())
   assert(lock1:release())
   print("waiting to finish...")
-  while next(tracker) do copas.sleep(0.1) end
+  while next(tracker) do copas.pause(0.1) end
   -- check results
   print("success: ", success_count)
   print("timeout: ", timeout_count)
diff --git a/tests/sleep.lua b/tests/pause.lua
similarity index 91%
rename from tests/sleep.lua
rename to tests/pause.lua
index e04cd0f..385dda8 100644
--- a/tests/sleep.lua
+++ b/tests/pause.lua
@@ -7,7 +7,7 @@ local copas = require("copas")
 
 local t1 = copas.addthread(
     function()
-        copas.sleep(-1)  -- sleep until woken up
+        copas.pauseforever()  -- sleep until woken up
     end
 )
 
diff --git a/tests/queue.lua b/tests/queue.lua
index 67f2e41..9329a60 100644
--- a/tests/queue.lua
+++ b/tests/queue.lua
@@ -19,7 +19,7 @@ copas.loop(function()
   -- yielding on pop when queue is empty
   local s = now()
   copas.addthread(function()
-    copas.sleep(0.5)
+    copas.pause(0.5)
     q:push("delayed")
   end)
   assert(q:pop() == "delayed", "expected a delayed result")
@@ -53,7 +53,7 @@ copas.loop(function()
   local coro = q:add_worker(function(item)
     count = count + 1
   end)
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(count == 3, "expected all 3 items handled")
   assert(coroutine.status(coro) == "dead", "expected thread to be gone")
   -- coro should be GC'able
@@ -86,7 +86,7 @@ print("test 1 success!")
 copas.loop(function()
   local q = Queue:new()
   q:add_worker(function() end)
-  copas.sleep(0.5) -- to activate the worker, which will now be blocked on the q semaphore
+  copas.pause(0.5) -- to activate the worker, which will now be blocked on the q semaphore
   q:stop()  -- this should exit the idle workers and exit the copas loop
 end)
 
diff --git a/tests/removeserver.lua b/tests/removeserver.lua
index a98cdc0..cf6a280 100644
--- a/tests/removeserver.lua
+++ b/tests/removeserver.lua
@@ -33,7 +33,7 @@ copas.addthread(function()
    for i = 1, 3 do
       wait_for_trigger()
       trigger_it(i)
-      copas.sleep(0.1)
+      copas.pause(0.1)
    end
 end)
 
diff --git a/tests/removethread.lua b/tests/removethread.lua
index 0e36818..ec1d14a 100644
--- a/tests/removethread.lua
+++ b/tests/removethread.lua
@@ -13,13 +13,13 @@ local t1 = copas.addthread(
         while true do
            n = n + 1
            print("endless thread:",n)
-           copas.sleep(0.5)
+           copas.pause(0.5)
         end
     end)
 
 local t2 = copas.addthread(function()
    for i = 1, 5 do
-      copas.sleep(0.6)
+      copas.pause(0.6)
    end
    print("stopping endless thread externally")
    copas.removethread(t1)
diff --git a/tests/request.lua b/tests/request.lua
index 3fdcfec..3d73135 100644
--- a/tests/request.lua
+++ b/tests/request.lua
@@ -25,7 +25,7 @@ end
 
 copas.addthread(function()
   while switches < max_switches do
-    copas.sleep(0)
+    copas.pause()
     switches = switches + 1
   end
 
diff --git a/tests/semaphore.lua b/tests/semaphore.lua
index 4d15ed6..6559a43 100644
--- a/tests/semaphore.lua
+++ b/tests/semaphore.lua
@@ -52,18 +52,18 @@ copas.loop(function()
     print("got the next 5!")
     state = state + 2
   end)
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(state == 0, "expected state to still be 0")
   assert(sema:get_count() == 2, "expected count to still have 2 resources")
 
   assert(sema:give(4))
   assert(sema:get_count() == 1, "expected count to now have 1 resource")
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(state == 1, "expected 1 from the first thread to be added to state")
 
   assert(sema:give(4))
   assert(sema:get_count() == 0, "gave 4 more, so 5 in total, releasing 5, leaves 0 as expected")
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(state == 3, "expected 2 from the 2nd thread to be added to state")
 
 
@@ -92,9 +92,9 @@ copas.loop(function()
       state = state + 1
     end
   end)
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(sema:destroy())
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(state == 2, "expected 2 threads to error with 'destroyed'")
 
   -- only returns errors from now on, on all methods
@@ -121,9 +121,9 @@ copas.loop(function()
       state = state + 1
     end
   end)
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(sema:destroy())
-  copas.sleep(0.1)
+  copas.pause(0.1)
   assert(state == 1, "expected 1 thread to error with 'destroyed'")
   sema = nil
 
@@ -137,7 +137,7 @@ copas.loop(function()
   collectgarbage()  -- collect garbage to force eviction from the semaphore registry
   collectgarbage()
 
-  copas.sleep(0.5) -- wait for the timeout to expire if it is still set
+  copas.pause(0.5) -- wait for the timeout to expire if it is still set
   assert(errors == 0, "expected no errors")
 
   test_complete = true
diff --git a/tests/starve.lua b/tests/starve.lua
index 127ca19..6d07d3b 100644
--- a/tests/starve.lua
+++ b/tests/starve.lua
@@ -63,7 +63,7 @@ local function runtest()
       local i = 0
       local start = socket.gettime()
       while done ~= 2 do
-        copas.sleep(1) -- delta sleep, so it slowly diverges if starved
+        copas.pause(1) -- delta sleep, so it slowly diverges if starved
         i = i + 1
         local time_passed = socket.gettime()-start
         print("slept "..i.." seconds, time passed: ".. time_passed.." seconds")
diff --git a/tests/timeout_errors.lua b/tests/timeout_errors.lua
index 70f2b98..d0411bd 100644
--- a/tests/timeout_errors.lua
+++ b/tests/timeout_errors.lua
@@ -23,7 +23,7 @@ function tests.error_on_timeout()
       error("oops...")
     end)
     print "going to sleep for 1 second"
-    copas.sleep(1)
+    copas.pause(1)
 
     if not (err_received or ""):find("oops...", 1, true) then
       print("expected to find the error string 'oops...', but got: " .. tostring(err_received))
diff --git a/tests/tls-sni.lua b/tests/tls-sni.lua
index 81a3cf8..94841b3 100644
--- a/tests/tls-sni.lua
+++ b/tests/tls-sni.lua
@@ -71,7 +71,7 @@ server = assert(socket.bind("*", port))
 copas.addserver(server, copas.handler(echoHandler, server_params))
 
 copas.addthread(function()
-  copas.sleep(0.5) -- allow server socket to be ready
+  copas.pause(0.5) -- allow server socket to be ready
 
   ----------------------
   -- Tests start here --