diff --git a/os/hal/include/st.h b/os/hal/include/st.h
index 05d382d93..b2cb00543 100644
--- a/os/hal/include/st.h
+++ b/os/hal/include/st.h
@@ -111,6 +111,17 @@
  * @api
  */
 #define stGetAlarm() st_lld_get_alarm()
+
+/**
+ * @brief   Determines if the alarm is active.
+ *
+ * @return              The alarm status.
+ * @retval false        if the alarm is not active.
+ * @retval true         is the alarm is active
+ *
+ * @api
+ */
+#define stIsAlarmActive() st_lld_is_alarm_active()
 /** @} */
 
 /*===========================================================================*/
diff --git a/os/hal/platforms/STM32/TIMv1/st_lld.h b/os/hal/platforms/STM32/TIMv1/st_lld.h
index 882472cb2..fb067f202 100644
--- a/os/hal/platforms/STM32/TIMv1/st_lld.h
+++ b/os/hal/platforms/STM32/TIMv1/st_lld.h
@@ -128,6 +128,20 @@ static inline systime_t st_lld_get_alarm(void) {
   return (systime_t)STM32_TIM2->CCR[0];
 }
 
+/**
+ * @brief   Determines if the alarm is active.
+ *
+ * @return              The alarm status.
+ * @retval false        if the alarm is not active.
+ * @retval true         is the alarm is active
+ *
+ * @notapi
+ */
+static inline bool st_lld_is_alarm_active(void) {
+
+  return (bool)((STM32_TIM2->DIER & STM32_TIM_DIER_CC1IE) != 0);
+}
+
 #endif /* _ST_LLD_H_ */
 
 /** @} */
diff --git a/os/rt/include/chdebug.h b/os/rt/include/chdebug.h
index ee49eec00..0fdc865eb 100644
--- a/os/rt/include/chdebug.h
+++ b/os/rt/include/chdebug.h
@@ -175,7 +175,7 @@ typedef struct {
 #endif /* !defined(chDbgCheck) */
 
 #else /* !CH_DBG_ENABLE_CHECKS */
-#define chDbgCheck(c) {(void)(c);}
+#define chDbgCheck(c) /*{(void)(c);}*/
 #endif /* !CH_DBG_ENABLE_CHECKS */
 
 #if CH_DBG_ENABLE_ASSERTS || defined(__DOXYGEN__)
@@ -200,7 +200,7 @@ typedef struct {
 }
 #endif /* !defined(chDbgAssert) */
 #else /* !CH_DBG_ENABLE_ASSERTS */
-#define chDbgAssert(c, r) {(void)(c);}
+#define chDbgAssert(c, r) /*{(void)(c);}*/
 #endif /* !CH_DBG_ENABLE_ASSERTS */
 /** @} */
 
diff --git a/os/rt/ports/ARMCMx/chcore_timer.h b/os/rt/ports/ARMCMx/chcore_timer.h
index 089ab2519..da3bd82de 100644
--- a/os/rt/ports/ARMCMx/chcore_timer.h
+++ b/os/rt/ports/ARMCMx/chcore_timer.h
@@ -37,6 +37,7 @@
 
 #else /* !defined(CH_PORT_DO_NOT_USE_ST) */
 
+/* This is the only header in the HAL designed to be include-able alone.*/
 #include "st.h"
 
 /*===========================================================================*/
@@ -90,6 +91,8 @@ static inline systime_t port_timer_get_time(void) {
  */
 static inline void port_timer_start_alarm(systime_t time) {
 
+  chDbgAssert(stIsAlarmActive() == false, "already active");
+
   stStartAlarm(time);
 }
 
@@ -100,6 +103,8 @@ static inline void port_timer_start_alarm(systime_t time) {
  */
 static inline void port_timer_stop_alarm(void) {
 
+  chDbgAssert(stIsAlarmActive() != false, "not active");
+
   stStopAlarm();
 }
 
@@ -112,6 +117,8 @@ static inline void port_timer_stop_alarm(void) {
  */
 static inline void port_timer_set_alarm(systime_t time) {
 
+  chDbgAssert(stIsAlarmActive() != false, "not active");
+
   stSetAlarm(time);
 }
 
@@ -124,6 +131,8 @@ static inline void port_timer_set_alarm(systime_t time) {
  */
 static inline systime_t port_timer_get_alarm(void) {
 
+  chDbgAssert(stIsAlarmActive() != false, "not active");
+
   return stGetAlarm();
 }