diff --git a/cpu/atmega2560/include/cpu_conf.h b/cpu/atmega2560/include/cpu_conf.h
index 4c32f88842037ea9c967b319cb80b787fb897e7a..2219a0af402826471fa70de34f8e044600e0fab1 100644
--- a/cpu/atmega2560/include/cpu_conf.h
+++ b/cpu/atmega2560/include/cpu_conf.h
@@ -17,8 +17,8 @@
  * @author          Hinnerk van Bruinehsen <h.v.bruinehsen@fu-berlin.de>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "atmega2560_regs.h"
 
@@ -47,5 +47,5 @@ extern "C" {
 }
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */
diff --git a/cpu/atmega_common/include/cpu.h b/cpu/atmega_common/include/cpu.h
index b7c7d83d2ff38d760a8d3b7fa802f2e999965389..4be4234a4bcee3b336236f0ab35388144a6ddf36 100644
--- a/cpu/atmega_common/include/cpu.h
+++ b/cpu/atmega_common/include/cpu.h
@@ -24,8 +24,8 @@
  * @author      Kaspar Schleiser <kaspar@schleiser.de>
  */
 
-#ifndef __ATMEGA_COMMON_H
-#define __ATMEGA_COMMON_H
+#ifndef ATMEGA_COMMON_H
+#define ATMEGA_COMMON_H
 
 #include <stdio.h>
 #include <stdint.h>
@@ -83,5 +83,5 @@ static inline void cpu_print_last_instruction(void)
 }
 #endif
 
-#endif /* __ATMEGA_COMMON_H */
+#endif /* ATMEGA_COMMON_H */
 /** @} */
diff --git a/cpu/cc2538/include/cpu_conf.h b/cpu/cc2538/include/cpu_conf.h
index 4a34f3f3d9d30ce43afc31fa62627cc85f1d811d..8c7695d46ec317fd5a49e20a80ae9c4c69095d47 100644
--- a/cpu/cc2538/include/cpu_conf.h
+++ b/cpu/cc2538/include/cpu_conf.h
@@ -16,8 +16,8 @@
  * @author          Ian Martin <ian@locicontrols.com>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "cpu_conf_common.h"
 #include "cc2538.h"
@@ -46,5 +46,5 @@ extern "C" {
 } /* end extern "C" */
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */
diff --git a/cpu/cortexm_common/include/cmsis_armcc.h b/cpu/cortexm_common/include/cmsis_armcc.h
index 682b36c9e3d030273ac81cc98a14c5207bd6aaa5..0866aeca7f2f3a6fd53de17f212a38426bd2c684 100644
--- a/cpu/cortexm_common/include/cmsis_armcc.h
+++ b/cpu/cortexm_common/include/cmsis_armcc.h
@@ -32,8 +32,8 @@
    ---------------------------------------------------------------------------*/
 
 
-#ifndef __CMSIS_ARMCC_H
-#define __CMSIS_ARMCC_H
+#ifndef CMSIS_ARMCC_H
+#define CMSIS_ARMCC_H
 
 #ifdef __cplusplus
  extern "C" {
@@ -737,4 +737,4 @@ __attribute__((section(".rrx_text"))) __STATIC_INLINE __ASM uint32_t __RRX(uint3
 }
 #endif
 
-#endif /* __CMSIS_ARMCC_H */
+#endif /* CMSIS_ARMCC_H */
diff --git a/cpu/cortexm_common/include/cmsis_armcc_V6.h b/cpu/cortexm_common/include/cmsis_armcc_V6.h
index b19533679b60d715471e4ca44bd80463d5a31fc2..82c36874468e5d8933d724ba30f2c048f4fd626f 100644
--- a/cpu/cortexm_common/include/cmsis_armcc_V6.h
+++ b/cpu/cortexm_common/include/cmsis_armcc_V6.h
@@ -32,8 +32,8 @@
    ---------------------------------------------------------------------------*/
 
 
-#ifndef __CMSIS_ARMCC_V6_H
-#define __CMSIS_ARMCC_V6_H
+#ifndef CMSIS_ARMCC_V6_H
+#define CMSIS_ARMCC_V6_H
 
 #ifdef __cplusplus
  extern "C" {
@@ -1804,4 +1804,4 @@ __attribute__((always_inline)) __STATIC_INLINE uint32_t __SMMLA (int32_t op1, in
 }
 #endif
 
-#endif /* __CMSIS_ARMCC_V6_H */
+#endif /* CMSIS_ARMCC_V6_H */
diff --git a/cpu/cortexm_common/include/cmsis_gcc.h b/cpu/cortexm_common/include/cmsis_gcc.h
index 2c303362a766e16a8454997acf402e16bb4e5fba..6a6987af314b08c3f17a9785947dcfb084da59ce 100644
--- a/cpu/cortexm_common/include/cmsis_gcc.h
+++ b/cpu/cortexm_common/include/cmsis_gcc.h
@@ -32,8 +32,8 @@
    ---------------------------------------------------------------------------*/
 
 
-#ifndef __CMSIS_GCC_H
-#define __CMSIS_GCC_H
+#ifndef CMSIS_GCC_H
+#define CMSIS_GCC_H
 
 #ifdef __cplusplus
  extern "C" {
@@ -1378,4 +1378,4 @@ __attribute__( ( always_inline ) ) __STATIC_INLINE uint32_t __SMMLA (int32_t op1
 }
 #endif
 
-#endif /* __CMSIS_GCC_H */
+#endif /* CMSIS_GCC_H */
diff --git a/cpu/ezr32wg/include/ezr32wg330f256r60.h b/cpu/ezr32wg/include/ezr32wg330f256r60.h
index e9754760db783de623b09e7a5886a0e364418c3d..663c413fcb8652d00f1594c9059ae505f6dd9c29 100644
--- a/cpu/ezr32wg/include/ezr32wg330f256r60.h
+++ b/cpu/ezr32wg/include/ezr32wg330f256r60.h
@@ -31,8 +31,8 @@
  *
  *****************************************************************************/
 
-#ifndef __SILICON_LABS_EZR32WG330F256R60_H__
-#define __SILICON_LABS_EZR32WG330F256R60_H__
+#ifndef SILICON_LABS_EZR32WG330F256R60_H__
+#define SILICON_LABS_EZR32WG330F256R60_H__
 
 #ifdef __cplusplus
 extern "C" {
@@ -492,4 +492,4 @@ typedef enum IRQn
 #ifdef __cplusplus
 }
 #endif
-#endif /* __SILICON_LABS_EZR32WG330F256R60_H__ */
+#endif /* SILICON_LABS_EZR32WG330F256R60_H__ */
diff --git a/cpu/k64f/include/cpu_conf.h b/cpu/k64f/include/cpu_conf.h
index 15cef19607082dbd1b40a8655ab34755d858ed0e..6906081d7d9742a319246b189718dea7db6ef686 100644
--- a/cpu/k64f/include/cpu_conf.h
+++ b/cpu/k64f/include/cpu_conf.h
@@ -21,8 +21,8 @@
  * @author          Johann Fischer <j.fischer@phytec.de>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "cpu_conf_common.h"
 
@@ -84,5 +84,5 @@ extern "C"
 }
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */
diff --git a/cpu/kinetis_common/include/mcg.h b/cpu/kinetis_common/include/mcg.h
index 034fb6f0e0961e5bcd54cf215adf0ede4d251709..7d12c768ea4a9e76aa113a74d510b77993aa5f56 100644
--- a/cpu/kinetis_common/include/mcg.h
+++ b/cpu/kinetis_common/include/mcg.h
@@ -97,8 +97,8 @@
  * @author      Johann Fischer <j.fischer@phytec.de>
  */
 
-#ifndef __MCG_CPU_H
-#define __MCG_CPU_H
+#ifndef MCG_CPU_H
+#define MCG_CPU_H
 
 #include "periph_conf.h"
 
@@ -130,7 +130,7 @@ int kinetis_mcg_set_mode(kinetis_mcg_mode_t mode);
 }
 #endif
 
-#endif /* __MCG_CPU_H */
+#endif /* KINETIS_CPU_USE_MCG */
 /** @} */
 
-#endif /* KINETIS_CPU_USE_MCG */
+#endif /* MCG_CPU_H */
diff --git a/cpu/kw2x/include/cpu_conf.h b/cpu/kw2x/include/cpu_conf.h
index 01d1baa7312405c9f5ae7f9d439449d9cae6c1e3..713e8a9942b94469de705b9de5fb6792ea7b4344 100644
--- a/cpu/kw2x/include/cpu_conf.h
+++ b/cpu/kw2x/include/cpu_conf.h
@@ -22,8 +22,8 @@
  * @author          Johann Fischer <j.fischer@phytec.de>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "cpu_conf_common.h"
 
@@ -115,5 +115,5 @@ extern "C"
 }
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */
diff --git a/cpu/lpc11u34/include/LPC11Uxx.h b/cpu/lpc11u34/include/LPC11Uxx.h
index 35afda35118fcd6a7b68b408b08e6ba54ac712e4..eab26b78a3227c39eb9870da0a517da0d80ada51 100644
--- a/cpu/lpc11u34/include/LPC11Uxx.h
+++ b/cpu/lpc11u34/include/LPC11Uxx.h
@@ -25,8 +25,8 @@
  *
  */
 
-#ifndef __LPC11UXX_H__
-#define __LPC11UXX_H__
+#ifndef LPC11UXX_H__
+#define LPC11UXX_H__
 
 #ifdef __cplusplus
 extern "C" {
@@ -662,5 +662,5 @@ typedef struct {
 #endif
 
 
-#endif  // __LPC11UXX_H__
+#endif  /* LPC11UXX_H__ */
 /** @} */
diff --git a/cpu/lpc11u34/include/cpu_conf.h b/cpu/lpc11u34/include/cpu_conf.h
index faecfc1e4eea75eab977f3de5bcce2275f423023..4acf87d56b63cfade6becf542cb227274915d4be 100644
--- a/cpu/lpc11u34/include/cpu_conf.h
+++ b/cpu/lpc11u34/include/cpu_conf.h
@@ -18,8 +18,8 @@
  * @author          Paul RATHGEB <paul.rathgeb@skynet.be>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "cpu_conf_common.h"
 
@@ -42,5 +42,5 @@ extern "C" {
 }
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */
diff --git a/cpu/lpc1768/include/LPC17xx.h b/cpu/lpc1768/include/LPC17xx.h
index 952cb73c66c09e2c7a0c81a400679888b075eb91..2a63feba2b5b2e80c0279a365276c6e682090fb7 100644
--- a/cpu/lpc1768/include/LPC17xx.h
+++ b/cpu/lpc1768/include/LPC17xx.h
@@ -23,8 +23,8 @@
  ******************************************************************************/
 
 
-#ifndef __LPC17xx_H__
-#define __LPC17xx_H__
+#ifndef LPC17xx_H__
+#define LPC17xx_H__
 
 #ifdef __cplusplus
 extern "C" {
@@ -1044,4 +1044,4 @@ typedef struct
 }
 #endif
 
-#endif  // __LPC17xx_H__
+#endif  /* LPC17xx_H__ */
diff --git a/cpu/lpc1768/include/cpu_conf.h b/cpu/lpc1768/include/cpu_conf.h
index 6eec80c60439317427fe896c6f7d6c98a8cee16e..f3dfab6fb5c69e077f721d457558261cc72f9d2d 100644
--- a/cpu/lpc1768/include/cpu_conf.h
+++ b/cpu/lpc1768/include/cpu_conf.h
@@ -18,8 +18,8 @@
  * @author          Hauke Petersen <hauke.peterse@fu-berlin.de>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "cpu_conf_common.h"
 
@@ -49,5 +49,5 @@ extern "C" {
 }
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */
diff --git a/cpu/lpc2387/include/cpu.h b/cpu/lpc2387/include/cpu.h
index fc8f179c4fe6513f0c797235273cf740f997a6e6..fddb45b025e6a1021b9411c1481b73624c88858b 100644
--- a/cpu/lpc2387/include/cpu.h
+++ b/cpu/lpc2387/include/cpu.h
@@ -6,8 +6,8 @@
  * directory for more details.
  */
 
-#ifndef __CPU_H
-#define __CPU_H
+#ifndef CPU_H
+#define CPU_H
 
 /**
  * @defgroup    lpc2387     NXP LPC2387
@@ -58,4 +58,4 @@ static inline void cpu_print_last_instruction(void)
 #endif
 
 /** @} */
-#endif /* __CPU_H */
+#endif /* CPU_H */
diff --git a/cpu/lpc2387/include/i2c.h b/cpu/lpc2387/include/i2c.h
index c7e4aaaa65fcc39a9d295cddf9c086821f5f20ed..9fbef8d3559a9f2b78fce5eda11c0b32f46e2996 100644
--- a/cpu/lpc2387/include/i2c.h
+++ b/cpu/lpc2387/include/i2c.h
@@ -28,8 +28,8 @@
  * @note        $Id: i2c.h 3857 2013-09-02 18:11:27 kasmi $
  */
 
-#ifndef __I2C_H
-#define __I2C_H
+#ifndef I2C_H
+#define I2C_H
 
 #include <stdbool.h>
 #include <stdint.h>
@@ -334,4 +334,4 @@ void i2c_disable_pull_up_resistor(uint8_t i2c_interface);
 }
 #endif
 
-#endif /* end __I2C_H */
+#endif /* I2C_H */
diff --git a/cpu/lpc2387/include/lpc2387.h b/cpu/lpc2387/include/lpc2387.h
index c16a3e11c6c56bd2dc856fa4d400fae3bd41ce1c..5c40c08e51221ad8d240185f758f6cd272afc206 100644
--- a/cpu/lpc2387/include/lpc2387.h
+++ b/cpu/lpc2387/include/lpc2387.h
@@ -8,8 +8,8 @@
  * Parts taken from FeuerWhere-Project, lpc2387.h.
  */
 
-#ifndef __LPC2387_H
-#define __LPC2387_H
+#ifndef LPC2387_H
+#define LPC2387_H
 
 #include "lpc23xx.h"
 #include "arm7_common.h"
@@ -151,4 +151,4 @@ extern "C" {
 }
 #endif
 
-#endif // __LPC2387_H
+#endif /* LPC2387_H */
diff --git a/cpu/saml21/include/cpu_conf.h b/cpu/saml21/include/cpu_conf.h
index fb0e41f7fb3506f15fe14b3e0b43085add759d74..413b59d284b4dafbd882937f41e605a3a944f1a2 100644
--- a/cpu/saml21/include/cpu_conf.h
+++ b/cpu/saml21/include/cpu_conf.h
@@ -15,8 +15,8 @@
  * @author          Thomas Eichinger <thomas.eichinger@fu-berlin.de>
  */
 
-#ifndef __CPU_CONF_H
-#define __CPU_CONF_H
+#ifndef CPU_CONF_H
+#define CPU_CONF_H
 
 #include "cpu_conf_common.h"
 
@@ -39,5 +39,5 @@ extern "C" {
 }
 #endif
 
-#endif /* __CPU_CONF_H */
+#endif /* CPU_CONF_H */
 /** @} */