diff --git a/cpu/stm32w108/hal/micro/cortexm3/micro-common-internal.c b/cpu/stm32w108/hal/micro/cortexm3/micro-common-internal.c
index a7cbc5c76..1bdeb36fa 100644
--- a/cpu/stm32w108/hal/micro/cortexm3/micro-common-internal.c
+++ b/cpu/stm32w108/hal/micro/cortexm3/micro-common-internal.c
@@ -46,7 +46,6 @@ void stCalibrateVref(void)
   // Calibrate Vref by measuring a known voltage, Vdd/2.
   //
   // FIXME: add support for calibration if done in boost mode.
-  extern int16u stmRadioTxPowerMode;
   tokTypeMfgAnalogueTrimBoth biasTrim;
   
   halCommonGetMfgToken(&biasTrim, TOKEN_MFG_ANALOG_TRIM_BOTH);
diff --git a/cpu/stm32w108/hal/micro/cortexm3/system-timer.c b/cpu/stm32w108/hal/micro/cortexm3/system-timer.c
index 12efe92f5..1f9b1f533 100644
--- a/cpu/stm32w108/hal/micro/cortexm3/system-timer.c
+++ b/cpu/stm32w108/hal/micro/cortexm3/system-timer.c
@@ -67,8 +67,8 @@ void halSleepTimerIsr(void)
   sleepTimerInterruptOccurred = TRUE;
 }
 
-#define CONVERT_QS_TO_TICKS(x) (x << 8)
-#define CONVERT_TICKS_TO_QS(x) (x >> 8)
+#define CONVERT_QS_TO_TICKS(x) ((x) << 8)
+#define CONVERT_TICKS_TO_QS(x) ((x) >> 8)
 #define TIMER_MAX_QS           0x1000000 // = 4194304 seconds * 4 = 16777216
 static StStatus internalSleepForQs(boolean useGpioWakeMask,
                                       int32u *duration,
diff --git a/cpu/stm32w108/hal/micro/system-timer.h b/cpu/stm32w108/hal/micro/system-timer.h
index 3b18651ac..965d3ec8b 100644
--- a/cpu/stm32w108/hal/micro/system-timer.h
+++ b/cpu/stm32w108/hal/micro/system-timer.h
@@ -48,9 +48,7 @@ int16u halInternalStartSystemTimer(void);
  * @return The least significant 16 bits of the current system time, in system
  * ticks.
  */
-#pragma pagezero_on  // place this function in zero-page memory for xap 
 int16u halCommonGetInt16uMillisecondTick(void);
-#pragma pagezero_off
 
 /**
  * @brief Returns the current system time in system ticks, as a 32-bit