diff --git a/cpu/stm32/periph/adc_f0.c b/cpu/stm32/periph/adc_f0.c
index 0d648352ef..9806d2eb7f 100644
--- a/cpu/stm32/periph/adc_f0.c
+++ b/cpu/stm32/periph/adc_f0.c
@@ -23,11 +23,6 @@
 #include "mutex.h"
 #include "periph/adc.h"
 
-/**
- * @brief   Maximum allowed ADC clock speed
- */
-#define MAX_ADC_SPEED           (12000000U)
-
 /**
  * @brief   Load the ADC configuration
  */
@@ -61,7 +56,7 @@ int adc_init(adc_t line)
 
     /* lock and power on the device */
     prep();
-    /*configure the pin */
+    /* configure the pin */
     gpio_init_analog(adc_config[line].pin);
     /* reset configuration */
     ADC1->CFGR2 = 0;
diff --git a/cpu/stm32/periph/adc_l0.c b/cpu/stm32/periph/adc_l0.c
index b35ecdca3d..682f302ad8 100644
--- a/cpu/stm32/periph/adc_l0.c
+++ b/cpu/stm32/periph/adc_l0.c
@@ -23,11 +23,6 @@
 #include "mutex.h"
 #include "periph/adc.h"
 
-/**
- * @brief   Maximum allowed ADC clock speed
- */
-#define MAX_ADC_SPEED           (12000000U)
-
 /**
  * @brief   Load the ADC configuration
  */
diff --git a/cpu/stm32/periph/adc_l1.c b/cpu/stm32/periph/adc_l1.c
index bbb7e215b9..77593532f5 100644
--- a/cpu/stm32/periph/adc_l1.c
+++ b/cpu/stm32/periph/adc_l1.c
@@ -25,11 +25,6 @@
 #include "mutex.h"
 #include "periph/adc.h"
 
-/**
- * @brief   Maximum allowed ADC clock speed
- */
-#define MAX_ADC_SPEED           (12000000U)
-
 /**
  * @brief   ADC clock settings
  *