diff --git a/arch/arm/src/stm32/stm32_pwm.c b/arch/arm/src/stm32/stm32_pwm.c
index 85ed3554fc9..48640f98690 100644
--- a/arch/arm/src/stm32/stm32_pwm.c
+++ b/arch/arm/src/stm32/stm32_pwm.c
@@ -1300,7 +1300,7 @@ static int pwm_timer(FAR struct stm32_pwmtimer_s *priv,
 
   timclk = priv->pclk / prescaler;
 
-  reload = timclk / info->frequency;
+  reload = timclk / info->frequency - 1;
   if (reload < 1)
     {
       reload = 1;
diff --git a/arch/arm/src/stm32l4/stm32l4_pwm.c b/arch/arm/src/stm32l4/stm32l4_pwm.c
index fe46e8cc4ef..3c0c8dab18f 100644
--- a/arch/arm/src/stm32l4/stm32l4_pwm.c
+++ b/arch/arm/src/stm32l4/stm32l4_pwm.c
@@ -841,7 +841,7 @@ static int stm32l4pwm_timer(FAR struct stm32l4_pwmtimer_s *priv,
 
   timclk = priv->pclk / prescaler;
 
-  reload = timclk / info->frequency;
+  reload = timclk / info->frequency - 1;
   if (reload < 1)
     {
       reload = 1;