diff --git a/cpu/stm32/periph/timer.c b/cpu/stm32/periph/timer.c
index 35eaab276b..6f5004177a 100644
--- a/cpu/stm32/periph/timer.c
+++ b/cpu/stm32/periph/timer.c
@@ -128,8 +128,6 @@ int timer_set_absolute(tim_t tim, int channel, unsigned int value)
     unsigned irqstate = irq_disable();
     set_oneshot(tim, channel);
 
-    TIM_CHAN(tim, channel) = (value & timer_config[tim].max);
-
 #ifdef MODULE_PERIPH_TIMER_PERIODIC
     if (dev(tim)->ARR == TIM_CHAN(tim, channel)) {
         dev(tim)->ARR = timer_config[tim].max;
@@ -139,6 +137,8 @@ int timer_set_absolute(tim_t tim, int channel, unsigned int value)
     /* clear spurious IRQs */
     dev(tim)->SR &= ~(TIM_SR_CC1IF << channel);
 
+    TIM_CHAN(tim, channel) = (value & timer_config[tim].max);
+
     /* enable IRQ */
     dev(tim)->DIER |= (TIM_DIER_CC1IE << channel);
     irq_restore(irqstate);
@@ -148,6 +148,8 @@ int timer_set_absolute(tim_t tim, int channel, unsigned int value)
 
 int timer_set(tim_t tim, int channel, unsigned int timeout)
 {
+    unsigned value = (dev(tim)->CNT + timeout) & timer_config[tim].max;
+
     if (channel >= (int)TIMER_CHANNEL_NUMOF) {
         return -1;
     }
@@ -155,21 +157,20 @@ int timer_set(tim_t tim, int channel, unsigned int timeout)
     unsigned irqstate = irq_disable();
     set_oneshot(tim, channel);
 
-    /* clear spurious IRQs */
-    dev(tim)->SR &= ~(TIM_SR_CC1IF << channel);
-
-    unsigned value = (dev(tim)->CNT + timeout) & timer_config[tim].max;
-    TIM_CHAN(tim, channel) = value;
-
-    /* enable IRQ */
-    dev(tim)->DIER |= (TIM_DIER_CC1IE << channel);
-
 #ifdef MODULE_PERIPH_TIMER_PERIODIC
     if (dev(tim)->ARR == TIM_CHAN(tim, channel)) {
         dev(tim)->ARR = timer_config[tim].max;
     }
 #endif
 
+    /* clear spurious IRQs */
+    dev(tim)->SR &= ~(TIM_SR_CC1IF << channel);
+
+    TIM_CHAN(tim, channel) = value;
+
+    /* enable IRQ */
+    dev(tim)->DIER |= (TIM_DIER_CC1IE << channel);
+
     /* calculate time till timeout */
     value = (value - dev(tim)->CNT) & timer_config[tim].max;