diff --git a/readme.txt b/readme.txt
index 499345d66..92a80bf84 100644
--- a/readme.txt
+++ b/readme.txt
@@ -40,7 +40,7 @@ AVR-AT90CANx-GCC       - Port on AVR AT90CAN128, not complete yet.
 *****************************************************************************
 
 *** 0.5.3 ***
-- Removed the chMsgSendTimeout() API, it was conceptually flawed because
+- Removed the chMsgSendTimeout() API, it was conceptually flawed because,
   after sending a message, the sender *has* to wait for the answer or
   the next sender in queue would receive it instead (the messages server has
   no way to know that the sender is gone because a timeout).
@@ -49,8 +49,9 @@ AVR-AT90CANx-GCC       - Port on AVR AT90CAN128, not complete yet.
 - Removed the test case for chMsgSendTimeout() from the test suite.
 - Space saved by reorganizing the timeout code into a single scheduler
   function.
+- Space optimizations in the semaphores code.
 - The API chThdSleepUntil() become a macro saving some more code space.
-- Because all the above changes the kernel code (ARM) is over 600 bytes
+- Because all the above changes the kernel code (ARM) is over 700 bytes
   smaller.
 
 *** 0.5.2 ***
diff --git a/src/chevents.c b/src/chevents.c
index 72ca7c182..9fd2e4543 100644
--- a/src/chevents.c
+++ b/src/chevents.c
@@ -53,9 +53,9 @@ void chEvtRegister(EventSource *esp, EventListener *elp, t_eventid eid) {
  * @param elp pointer to the \p EventListener structure
  * @note If the event listener is not registered on the specified event source
  *       then the function does nothing.
- * @note For optimal performance perform the unregister operations in inverse
- *       order of the register operations (elements are found on top of the
- *       list).
+ * @note For optimal performance it is better to perform the unregister
+ *       operations in inverse order of the register operations (elements are
+ *       found on top of the list).
  */
 void chEvtUnregister(EventSource *esp, EventListener *elp) {
   EventListener *p = (EventListener *)esp;
diff --git a/src/chschd.c b/src/chschd.c
index 92a0fbb0d..1242ea275 100644
--- a/src/chschd.c
+++ b/src/chschd.c
@@ -90,6 +90,7 @@ void chSchGoSleepS(t_tstate newstate) {
   chSysSwitchI(otp, currp);
 }
 
+#ifdef CH_USE_VIRTUAL_TIMERS
 static void wakeup(void *p) {
 
   if (((Thread *)p)->p_state == PRWTSEM)
@@ -116,6 +117,7 @@ t_msg chSchGoSleepTimeoutS(t_tstate newstate, t_time time) {
     chVTResetI(&vt);
   return currp->p_rdymsg;
 }
+#endif /* CH_USE_VIRTUAL_TIMERS */
 
 /**
  * Wakeups a thread, the thread is inserted into the ready list or made
diff --git a/src/chsem.c b/src/chsem.c
index ceaa64399..edec3b5db 100644
--- a/src/chsem.c
+++ b/src/chsem.c
@@ -47,18 +47,11 @@ void chSemInit(Semaphore *sp, t_cnt n) {
  *       \p RDY_RESET.
  */
 void chSemReset(Semaphore *sp, t_cnt n) {
-  t_cnt cnt;
 
-  chDbgAssert(n >= 0, "chsem.c, chSemReset()");
   chSysLock();
 
-  cnt = sp->s_cnt;
-  sp->s_cnt = n;
-  if (cnt < 0) {
-    while (cnt++)
-      chSchReadyI(fifo_remove(&sp->s_queue), RDY_RESET);
-    chSchRescheduleS();
-  }
+  chSemResetI(sp, n);
+  chSchRescheduleS();
 
   chSysUnlock();
 }