diff --git a/dist/tools/riotboot_gen_hdr/Makefile b/dist/tools/riotboot_gen_hdr/Makefile
index dd57e45f27..61ed4cda8a 100644
--- a/dist/tools/riotboot_gen_hdr/Makefile
+++ b/dist/tools/riotboot_gen_hdr/Makefile
@@ -11,7 +11,7 @@ RIOT_HDR_SRC := \
 
 RIOT_HDR_HDR := $(RIOT_INCLUDE)/riotboot/hdr.h \
 	$(RIOT_INCLUDE)/checksum/fletcher32.h \
-	$(RIOTBASE)/core/include/byteorder.h
+	$(RIOTBASE)/sys/include/byteorder.h
 
 GENHDR_SRC := $(COMMON_SRC) $(RIOT_HDR_SRC) \
 	main.c genhdr.c
diff --git a/core/include/byteorder.h b/sys/include/byteorder.h
similarity index 99%
rename from core/include/byteorder.h
rename to sys/include/byteorder.h
index 61d8ebd39a..2684d7d943 100644
--- a/core/include/byteorder.h
+++ b/sys/include/byteorder.h
@@ -7,7 +7,7 @@
  */
 
 /**
- * @ingroup     core_util
+ * @ingroup     sys
  * @{
  *
  * @file