diff --git a/lib/trinity/sim_process.ex b/lib/trinity/sim_process.ex
index f76904c..6ef5742 100644
--- a/lib/trinity/sim_process.ex
+++ b/lib/trinity/sim_process.ex
@@ -42,6 +42,15 @@ defmodule Trinity.SimProcess do
     end
   end
 
+  @spec sleep(term) :: :ok
+  def sleep(timeout) do
+    case get_sim() do
+      nil -> Process.sleep(timeout)
+      _sim -> Trinity.Scheduler.yield(timeout)
+    end
+    :ok
+  end
+
   @spec flag(atom, term) :: term
   def flag(flag, value) do
     case get_sim() do