diff --git a/cpu/stm32f3/include/periph_cpu.h b/cpu/stm32f3/include/periph_cpu.h
index 63f12ffa348be..b81d3157c7547 100644
--- a/cpu/stm32f3/include/periph_cpu.h
+++ b/cpu/stm32f3/include/periph_cpu.h
@@ -48,16 +48,6 @@ typedef struct {
     uint8_t chan;           /**< DAC device used for this line */
 } dac_conf_t;
 
-/**
- * @brief   Configure the alternate function for the given pin
- *
- * @note    This is meant for internal use in STM32F4 peripheral drivers only
- *
- * @param[in] pin       pin to configure
- * @param[in] af        alternate function to use
- */
-void gpio_init_af(gpio_t pin, gpio_af_t af);
-
 #ifdef __cplusplus
 }
 #endif
diff --git a/cpu/stm32l1/include/periph_cpu.h b/cpu/stm32l1/include/periph_cpu.h
index b448ceedb0189..cfb5e4788800b 100644
--- a/cpu/stm32l1/include/periph_cpu.h
+++ b/cpu/stm32l1/include/periph_cpu.h
@@ -62,16 +62,6 @@ typedef struct {
     uint8_t ev_irqn;        /**< event IRQ */
 } i2c_conf_t;
 
-/**
- * @brief   Configure the alternate function for the given pin
- *
- * @note    This is meant for internal use in STM32L1 peripheral drivers only
- *
- * @param[in] pin       pin to configure
- * @param[in] af        alternate function to use
- */
-void gpio_init_af(gpio_t pin, gpio_af_t af);
-
 #ifdef __cplusplus
 }
 #endif