diff --git a/cpu/nrf51/periph/adc.c b/cpu/nrf51/periph/adc.c
index 6b6080b0f08bc..f84acb790b146 100644
--- a/cpu/nrf51/periph/adc.c
+++ b/cpu/nrf51/periph/adc.c
@@ -25,15 +25,11 @@
 #include "periph/adc.h"
 #include "periph_conf.h"
 
+#ifdef ADC_CONFIG
 /**
  * @brief   Load the ADC configuration
- * @{
  */
-#ifdef ADC_CONFIG
 static const uint8_t adc_config[] = ADC_CONFIG;
-#else
-static const uint8_t adc_config[] = {};
-#endif
 
 /**
  * @brief   Lock to prevent concurrency issues when used from different threads
@@ -91,3 +87,4 @@ int adc_sample(adc_t line, adc_res_t res)
 
     return val;
 }
+#endif /* ADC_CONFIG */
diff --git a/cpu/stm32_common/periph/dac.c b/cpu/stm32_common/periph/dac.c
index d250802c9355a..da831ffaad411 100644
--- a/cpu/stm32_common/periph/dac.c
+++ b/cpu/stm32_common/periph/dac.c
@@ -26,6 +26,7 @@
 
 /* only compile this, if the CPU has a DAC */
 #if defined(DAC) || defined(DAC1)
+#ifdef DAC_CONFIG
 
 #ifdef DAC2
 #define _DAC(line)          (dac_config[line].dac ? DAC2 : DAC1)
@@ -34,15 +35,9 @@
 #endif
 
 /**
- * @brief   Get the DAC configuration from the board (if configured)
- * @{
+ * @brief   Get the DAC configuration from the board config
  */
-#ifdef DAC_CONFIG
 static const dac_conf_t dac_config[] = DAC_CONFIG;
-#else
-static const dac_conf_t dac_config[] = {};
-#endif
-/** @} */
 
 int8_t dac_init(dac_t line)
 {
@@ -96,4 +91,5 @@ void dac_poweroff(dac_t line)
     DAC->CR &= ~(1 << (16 * dac_config[line].chan));
 }
 
+#endif /* DAC_CONFIG */
 #endif /* DAC */
diff --git a/cpu/stm32f0/periph/adc.c b/cpu/stm32f0/periph/adc.c
index d21b3625eb32a..d9c1d2071a73d 100644
--- a/cpu/stm32f0/periph/adc.c
+++ b/cpu/stm32f0/periph/adc.c
@@ -22,6 +22,8 @@
 #include "mutex.h"
 #include "periph/adc.h"
 
+#ifdef ADC_CONFIG
+
 /**
  * @brief   Maximum allowed ADC clock speed
  */
@@ -29,13 +31,8 @@
 
 /**
  * @brief   Load the ADC configuration
- * @{
  */
-#ifdef ADC_CONFIG
 static const adc_conf_t adc_config[] = ADC_CONFIG;
-#else
-static const adc_conf_t adc_config[] = {};
-#endif
 
 /**
  * @brief   Allocate locks for all three available ADC device
@@ -105,3 +102,5 @@ int adc_sample(adc_t line,  adc_res_t res)
 
     return sample;
 }
+
+#endif /* ADC_CONFIG */
diff --git a/cpu/stm32f1/periph/adc.c b/cpu/stm32f1/periph/adc.c
index b9bbc616a0b6a..e5a50798ebd73 100644
--- a/cpu/stm32f1/periph/adc.c
+++ b/cpu/stm32f1/periph/adc.c
@@ -24,6 +24,8 @@
 #include "periph/adc.h"
 #include "periph_conf.h"
 
+#ifdef ADC_CONFIG
+
 /**
  * @brief   Maximum allowed ADC clock speed
  */
@@ -31,13 +33,8 @@
 
 /**
  * @brief   Load the ADC configuration
- * @{
  */
-#ifdef ADC_CONFIG
 static const adc_conf_t adc_config[] = ADC_CONFIG;
-#else
-static const adc_conf_t adc_config[] = {};
-#endif
 
 /**
  * @brief   Allocate locks for all three available ADC devices
@@ -159,3 +156,5 @@ int adc_sample(adc_t line, adc_res_t res)
 
     return sample;
 }
+
+#endif /* ADC_CONFIG */
diff --git a/cpu/stm32f4/periph/adc.c b/cpu/stm32f4/periph/adc.c
index 410cf36767455..17b4a80fab5a9 100644
--- a/cpu/stm32f4/periph/adc.c
+++ b/cpu/stm32f4/periph/adc.c
@@ -23,6 +23,8 @@
 #include "periph/adc.h"
 #include "periph_conf.h"
 
+#ifdef ADC_CONFIG
+
 /**
  * @brief   Maximum allowed ADC clock speed
  */
@@ -30,13 +32,8 @@
 
 /**
  * @brief   Load the ADC configuration
- * @{
  */
-#ifdef ADC_CONFIG
 static const adc_conf_t adc_config[] = ADC_CONFIG;
-#else
-static const adc_conf_t adc_config[] = {};
-#endif
 
 /**
  * @brief   Allocate locks for all three available ADC devices
@@ -124,3 +121,5 @@ int adc_sample(adc_t line, adc_res_t res)
 
     return sample;
 }
+
+#endif /* ADC_CONFIG */