diff --git a/test/fiddle/test_function.rb b/test/fiddle/test_function.rb
index 847df3793a..1785f492ad 100644
--- a/test/fiddle/test_function.rb
+++ b/test/fiddle/test_function.rb
@@ -180,13 +180,13 @@ module Fiddle
       end
       f = Function.new(poll, [TYPE_VOIDP, TYPE_INT, TYPE_INT], TYPE_INT)
 
-      msec = 200
+      msec = EnvUtil.apply_timeout_scale(1000)
       t0 = Process.clock_gettime(Process::CLOCK_MONOTONIC, :millisecond)
       th = Thread.new { f.call(nil, 0, msec) }
       n1 = f.call(nil, 0, msec)
       n2 = th.value
       t1 = Process.clock_gettime(Process::CLOCK_MONOTONIC, :millisecond)
-      assert_in_delta(msec, t1 - t0, 180, 'slept amount of time')
+      assert_in_delta(msec, t1 - t0, EnvUtil.apply_timeout_scale(500), 'slept amount of time')
       assert_equal(0, n1, perror("poll(2) in main-thread"))
       assert_equal(0, n2, perror("poll(2) in sub-thread"))
     end