diff --git a/sys/kern/kern_sig.pas b/sys/kern/kern_sig.pas
index 3a4f9f36..11be3c55 100644
--- a/sys/kern/kern_sig.pas
+++ b/sys/kern/kern_sig.pas
@@ -1785,8 +1785,6 @@ begin
 
  thread_unlock(td);
 
- md_test_alert;
-
  if ((flags and TDF_ALRMPEND)<>0) then
  begin
   PROC_LOCK;
diff --git a/sys/kern/sched_ule.pas b/sys/kern/sched_ule.pas
index cea85c18..c5425cae 100644
--- a/sys/kern/sched_ule.pas
+++ b/sys/kern/sched_ule.pas
@@ -131,6 +131,9 @@ begin
  Result:=msleep_td(slptick);
 
  thread_lock(td);
+
+ //reset thread wakeup queue after lock
+ md_reset_wakeup;
 end;
 
 function setrunnable(td:p_kthread):Integer;
diff --git a/sys/kern/subr_sleepqueue.pas b/sys/kern/subr_sleepqueue.pas
index cd52cfa0..36a0efa6 100644
--- a/sys/kern/subr_sleepqueue.pas
+++ b/sys/kern/subr_sleepqueue.pas
@@ -262,7 +262,8 @@ begin
  Assert(td^.td_sleepqueue=nil);
  Assert(wchan<>nil);
 
- td^.td_slptick:=time;
+ //Hack: callout_reset_curcpu(@td^.td_slpcallout, timo, sleepq_timeout, td);
+ td^.td_slptick   :=time;
  td^.td_slpcallout:=@sleepq_timeout;
 end;
 
@@ -440,6 +441,8 @@ begin
 
  r:=mi_switch(SW_VOL or SWT_SLEEPQ);
 
+ //Hack: call sleepq_timeout on timeout
+ if (r=ETIMEDOUT) then
  if (td^.td_slpcallout=Pointer(@sleepq_timeout)) then
  begin
   sleepq_timeout(td);
@@ -450,7 +453,10 @@ begin
  mtx_lock(td^.tdq_lock);
  thread_lock_set(td,@td^.tdq_lock);
 
- Assert(TD_IS_RUNNING(td),'running but not TDS_RUNNING');
+ if not TD_IS_RUNNING(td) then
+ begin
+  Assert(false,'running but not TDS_RUNNING');
+ end;
 end;
 
 {
@@ -474,6 +480,11 @@ begin
  if ((td^.td_flags and TDF_TIMOFAIL)<>0) then
  begin
   td^.td_flags:=td^.td_flags and (not TDF_TIMOFAIL);
+ end else
+ begin
+  //Hack: callout_stop(@td^.td_slpcallout)
+  td^.td_slptick   :=0;
+  td^.td_slpcallout:=nil;
  end;
 end;
 
diff --git a/sys/md/md_context.pas b/sys/md/md_context.pas
index 93e48355..c55c6b8e 100644
--- a/sys/md/md_context.pas
+++ b/sys/md/md_context.pas
@@ -105,8 +105,6 @@ procedure _set_ucontext(dst:PCONTEXT;src:p_ucontext_t);
 
 function  md_get_fpcontext(td:p_kthread;mcp:p_mcontext_t;xstate:Pointer):Integer;
 
-procedure md_test_alert;
-
 procedure ipi_sigreturn;
 function  ipi_send_cpu(td:p_kthread):Integer;
 
@@ -600,11 +598,6 @@ begin
  //xmm,ymm
 end;
 
-procedure md_test_alert;
-begin
- NtTestAlert();
-end;
-
 procedure switch_to_jit(td:p_kthread); external;
 
 procedure ipi_sigreturn;
diff --git a/sys/md/md_sleep.pas b/sys/md/md_sleep.pas
index 06cc2b00..0cecd960 100644
--- a/sys/md/md_sleep.pas
+++ b/sys/md/md_sleep.pas
@@ -12,6 +12,7 @@ uses
 
 function  msleep_td(timo:Int64):Integer;
 function  wakeup_td(td:p_kthread):Integer;
+procedure md_reset_wakeup;
 procedure md_yield;
 
 implementation
@@ -69,6 +70,11 @@ begin
  Result:=ntw2px(NtQueueApcThread(td^.td_handle,@_apc_null,nil,nil,0));
 end;
 
+procedure md_reset_wakeup;
+begin
+ NtTestAlert();
+end;
+
 procedure md_yield;
 begin
  NtYieldExecution;