diff --git a/boards/ikea-tradfri/include/board.h b/boards/ikea-tradfri/include/board.h
index ffb784a3fa..8292d7dc21 100644
--- a/boards/ikea-tradfri/include/board.h
+++ b/boards/ikea-tradfri/include/board.h
@@ -22,7 +22,6 @@
 #define BOARD_H
 
 #include "cpu.h"
-
 #include "periph_conf.h"
 #include "periph/gpio.h"
 #include "periph/spi.h"
diff --git a/boards/ikea-tradfri/include/periph_conf.h b/boards/ikea-tradfri/include/periph_conf.h
index 54987ab063..0af367fd21 100644
--- a/boards/ikea-tradfri/include/periph_conf.h
+++ b/boards/ikea-tradfri/include/periph_conf.h
@@ -20,9 +20,7 @@
 #define PERIPH_CONF_H
 
 #include "cpu.h"
-
 #include "periph_cpu.h"
-
 #include "em_cmu.h"
 
 #ifdef __cplusplus
diff --git a/boards/sltb001a/board.c b/boards/sltb001a/board.c
index 3ebbbd1144..d90477d69c 100644
--- a/boards/sltb001a/board.c
+++ b/boards/sltb001a/board.c
@@ -21,9 +21,8 @@
 
 #include "board.h"
 #include "board_common.h"
-#include "pic.h"
-
 #include "periph/gpio.h"
+#include "pic.h"
 
 void board_init(void)
 {
diff --git a/boards/sltb001a/include/board.h b/boards/sltb001a/include/board.h
index ead4796d49..b398b623b6 100644
--- a/boards/sltb001a/include/board.h
+++ b/boards/sltb001a/include/board.h
@@ -23,7 +23,6 @@
 #define BOARD_H
 
 #include "cpu.h"
-
 #include "periph_conf.h"
 #include "periph/gpio.h"
 #include "periph/spi.h"
diff --git a/boards/sltb001a/include/periph_conf.h b/boards/sltb001a/include/periph_conf.h
index b54d77f406..552a786418 100644
--- a/boards/sltb001a/include/periph_conf.h
+++ b/boards/sltb001a/include/periph_conf.h
@@ -21,9 +21,7 @@
 #define PERIPH_CONF_H
 
 #include "cpu.h"
-
 #include "periph_cpu.h"
-
 #include "em_cmu.h"
 
 #ifdef __cplusplus
diff --git a/boards/stk3600/include/board.h b/boards/stk3600/include/board.h
index 50a6c1bc04..0ecc3e3d06 100644
--- a/boards/stk3600/include/board.h
+++ b/boards/stk3600/include/board.h
@@ -23,7 +23,6 @@
 #define BOARD_H
 
 #include "cpu.h"
-
 #include "periph_conf.h"
 #include "periph/gpio.h"
 #include "periph/spi.h"
diff --git a/boards/stk3600/include/periph_conf.h b/boards/stk3600/include/periph_conf.h
index 4a29d9ef9f..accf1d2d89 100644
--- a/boards/stk3600/include/periph_conf.h
+++ b/boards/stk3600/include/periph_conf.h
@@ -21,9 +21,7 @@
 #define PERIPH_CONF_H
 
 #include "cpu.h"
-
 #include "periph_cpu.h"
-
 #include "em_cmu.h"
 
 #ifdef __cplusplus
diff --git a/boards/stk3700/include/board.h b/boards/stk3700/include/board.h
index 403afc6b80..26644197f8 100644
--- a/boards/stk3700/include/board.h
+++ b/boards/stk3700/include/board.h
@@ -23,7 +23,6 @@
 #define BOARD_H
 
 #include "cpu.h"
-
 #include "periph_conf.h"
 #include "periph/gpio.h"
 #include "periph/spi.h"
diff --git a/boards/stk3700/include/periph_conf.h b/boards/stk3700/include/periph_conf.h
index 2babb66454..dd0440e59f 100644
--- a/boards/stk3700/include/periph_conf.h
+++ b/boards/stk3700/include/periph_conf.h
@@ -21,9 +21,7 @@
 #define PERIPH_CONF_H
 
 #include "cpu.h"
-
 #include "periph_cpu.h"
-
 #include "em_cmu.h"
 
 #ifdef __cplusplus