diff --git a/cpu/esp8266/include/periph_cpu.h b/cpu/esp8266/include/periph_cpu.h
index f404c52721..a1d5be5973 100644
--- a/cpu/esp8266/include/periph_cpu.h
+++ b/cpu/esp8266/include/periph_cpu.h
@@ -27,16 +27,6 @@
 extern "C" {
 #endif
 
-/**
- * @brief   Override the ADC resolution configuration
- * @{
- */
-#define HAVE_ADC_RES_T
-typedef enum {
-    ADC_RES_10BIT      /* only one resolution is supported */
-} adc_res_t;
-/** @} */
-
 /**
  * @brief   Length of the CPU_ID in octets
  */