diff --git a/drv/stk.c b/drv/stk.c
index d865738..a86811f 100644
--- a/drv/stk.c
+++ b/drv/stk.c
@@ -21,6 +21,7 @@ static volatile struct STK* regs = (struct STK*)STK_BASE_ADDRESS;
 //--local variables-------------------------------------------------------------
 
 static StkCallback callback;
+static uint32_t prescaler;
 
 
 //--public functions------------------------------------------------------------
@@ -32,10 +33,12 @@ uint32_t stk_configure(uint32_t period_us, StkCallback cb)
 	struct RccClocks clocks;
 	rcc_get_clocks(&clocks);
 
-	uint32_t reload = period_us * (clocks.ahb_freq / 1000000 / 8);
+	uint32_t prescaler = (clocks.ahb_freq / 1000000 / 8);
+	uint32_t reload = period_us * prescaler;
 	if (reload < 1) {
 		//period is too small, try using the non-prescaled clock
-		reload = period_us * (clocks.ahb_freq / 1000000);
+		prescaler *= 8;
+		reload = period_us * prescaler;
 		if (reload < 1) {
 			//period is still too small
 			return 1;
@@ -71,9 +74,9 @@ void stk_stop(void)
 	reg_reset(regs->CTRL, STK_CTRL_ENABLE);
 }
 
-uint32_t stk_read(void)
+uint32_t stk_read_us(void)
 {
-	return regs->VAL.word & 0x00FFFFFF;
+	return (regs->VAL.word & 0x00FFFFFF) / prescaler;
 }
 
 
diff --git a/drv/stk.h b/drv/stk.h
index d5c5d1d..9cdd685 100644
--- a/drv/stk.h
+++ b/drv/stk.h
@@ -46,9 +46,9 @@ void stk_start(void);
 void stk_stop(void);
 
 /**
- * Read the current value of the timer's counter
+ * Read the current value of the timer's counter in µs
  */
-uint32_t stk_read(void);
+uint32_t stk_read_us(void);
 
 
 #endif //_STK_H_
diff --git a/srv/task.c b/srv/task.c
index 0c40a82..0baba14 100644
--- a/srv/task.c
+++ b/srv/task.c
@@ -73,7 +73,7 @@ void task_start_scheduler(void)
 			stk_start();
 			__asm("wfi");
 			stk_stop();
-			uint32_t stk_delay = stk_read();
+			uint32_t stk_delay = stk_read_us();
 			if (stk_delay != 0) {
 				delay = stk_delay;
 			}