diff --git a/src/testdir/test_timers.vim b/src/testdir/test_timers.vim
index f40213d..3eebad6 100644
--- a/src/testdir/test_timers.vim
+++ b/src/testdir/test_timers.vim
@@ -162,8 +162,16 @@
 func Test_timer_stop_in_callback()
   call assert_equal(0, len(timer_info()))
   let g:timer1 = timer_start(10, 'StopTimer1')
-  sleep 50m
-  call assert_equal(0, len(timer_info()))
+  let slept = 0
+  for i in range(10)
+    if len(timer_info()) == 0
+      break
+    endif
+    sleep 10m
+    let slept += 10
+  endfor
+  " This should take only 30 msec, but on Mac it's often longer
+  call assert_inrange(0, 50, slept)
 endfunc
 
 func StopTimerAll(timer)