diff --git a/boards/nrf52840dk/include/periph_conf.h b/boards/nrf52840dk/include/periph_conf.h
index 936e2fcc97..b615b9030c 100644
--- a/boards/nrf52840dk/include/periph_conf.h
+++ b/boards/nrf52840dk/include/periph_conf.h
@@ -20,6 +20,7 @@
 #ifndef PERIPH_CONF_H
 #define PERIPH_CONF_H
 
+#include "kernel_defines.h"
 #include "periph_conf_common.h"
 
 #ifdef __cplusplus
diff --git a/cpu/nrf5x_common/include/nrfx.h b/cpu/nrf5x_common/include/nrfx.h
index 1edb426cf7..fcd137d9e8 100644
--- a/cpu/nrf5x_common/include/nrfx.h
+++ b/cpu/nrf5x_common/include/nrfx.h
@@ -22,6 +22,7 @@
 #ifndef NRFX_H
 #define NRFX_H
 
+#include "kernel_defines.h"
 #include "cpu_conf.h"
 #include "periph_conf.h"