diff --git a/sys/include/crypto/ciphers.h b/sys/include/crypto/ciphers.h
index 1e3c8bd9c5..fcada82b40 100644
--- a/sys/include/crypto/ciphers.h
+++ b/sys/include/crypto/ciphers.h
@@ -19,8 +19,8 @@
  * @author      Mark Essien <markessien@gmail.com>
  */
 
-#ifndef __CIPHERS_H_
-#define __CIPHERS_H_
+#ifndef CRYPTO_CIPHERS_H_
+#define CRYPTO_CIPHERS_H_
 
 #include <stdint.h>
 
@@ -169,4 +169,4 @@ int cipher_get_block_size(const cipher_t* cipher);
 #endif
 
 /** @} */
-#endif /* __CIPHERS_H_ */
+#endif /* CRYPTO_CIPHERS_H_ */
diff --git a/sys/include/crypto/helper.h b/sys/include/crypto/helper.h
index 81b72ab105..5af1551017 100644
--- a/sys/include/crypto/helper.h
+++ b/sys/include/crypto/helper.h
@@ -17,8 +17,8 @@
  * @author      Nico von Geyso <nico.geyso@fu-berlin.de>
  */
 
-#ifndef __CRYPTO_MODES_HELPER_H_
-#define __CRYPTO_MODES_HELPER_H_
+#ifndef CRYPTO_MODES_HELPER_H_
+#define CRYPTO_MODES_HELPER_H_
 
 #include <stddef.h>
 #include <stdint.h>
@@ -53,4 +53,4 @@ int crypto_equals(uint8_t *a, uint8_t *b, size_t len);
 }
 #endif
 
-#endif /* __CRYPTO_MODES_HELPER_H_ */
+#endif /* CRYPTO_MODES_HELPER_H_ */
diff --git a/sys/include/crypto/modes/cbc.h b/sys/include/crypto/modes/cbc.h
index 79a9db7621..338066fd8a 100644
--- a/sys/include/crypto/modes/cbc.h
+++ b/sys/include/crypto/modes/cbc.h
@@ -17,8 +17,8 @@
  * @author      Nico von Geyso <nico.geyso@fu-berlin.de>
  */
 
-#ifndef __CRYPTO_MODES_CBC_H_
-#define __CRYPTO_MODES_CBC_H_
+#ifndef CRYPTO_MODES_CBC_H_
+#define CRYPTO_MODES_CBC_H_
 
 #include "crypto/ciphers.h"
 
@@ -58,4 +58,4 @@ int cipher_decrypt_cbc(cipher_t* cipher, uint8_t iv[16], uint8_t* input,
 }
 #endif
 
-#endif /* __CRYPTO_MODES_CBC_H_ */
+#endif /* CRYPTO_MODES_CBC_H_ */
diff --git a/sys/include/crypto/modes/ccm.h b/sys/include/crypto/modes/ccm.h
index 7c36d2fe91..6f31704b50 100644
--- a/sys/include/crypto/modes/ccm.h
+++ b/sys/include/crypto/modes/ccm.h
@@ -17,8 +17,8 @@
  * @author      Nico von Geyso <nico.geyso@fu-berlin.de>
  */
 
-#ifndef __CRYPTO_MODES_CCM_H_
-#define __CRYPTO_MODES_CCM_H_
+#ifndef CRYPTO_MODES_CCM_H_
+#define CRYPTO_MODES_CCM_H_
 
 #include "crypto/ciphers.h"
 
@@ -85,4 +85,4 @@ int cipher_decrypt_ccm(cipher_t* cipher, uint8_t* auth_data,
 }
 #endif
 
-#endif /* __CRYPTO_MODES_CCM_H_ */
+#endif /* CRYPTO_MODES_CCM_H_ */
diff --git a/sys/include/crypto/modes/ctr.h b/sys/include/crypto/modes/ctr.h
index de1bdd658d..e1ce1ad7d1 100644
--- a/sys/include/crypto/modes/ctr.h
+++ b/sys/include/crypto/modes/ctr.h
@@ -17,8 +17,8 @@
  * @author      Nico von Geyso <nico.geyso@fu-berlin.de>
  */
 
-#ifndef __CRYPTO_MODES_CTR_H_
-#define __CRYPTO_MODES_CTR_H_
+#ifndef CRYPTO_MODES_CTR_H_
+#define CRYPTO_MODES_CTR_H_
 
 #include "crypto/ciphers.h"
 
@@ -70,4 +70,4 @@ int cipher_decrypt_ctr(cipher_t* cipher, uint8_t nonce_counter[16],
 }
 #endif
 
-#endif /* __CRYPTO_MODES_CTR_H_*/
+#endif /* CRYPTO_MODES_CTR_H_*/
diff --git a/sys/include/crypto/modes/ecb.h b/sys/include/crypto/modes/ecb.h
index a7d8524a8d..4c0738c6bb 100644
--- a/sys/include/crypto/modes/ecb.h
+++ b/sys/include/crypto/modes/ecb.h
@@ -17,8 +17,8 @@
  * @author      Nico von Geyso <nico.geyso@fu-berlin.de>
  */
 
-#ifndef __CRYPTO_MODES_ECB_H_
-#define __CRYPTO_MODES_ECB_H_
+#ifndef CRYPTO_MODES_ECB_H_
+#define CRYPTO_MODES_ECB_H_
 
 #include "crypto/ciphers.h"
 
@@ -59,4 +59,4 @@ int cipher_decrypt_ecb(cipher_t* cipher, uint8_t* input, size_t length,
 }
 #endif
 
-#endif /* __CRYPTO_MODES_ECB_H_*/
+#endif /* CRYPTO_MODES_ECB_H_*/