diff --git a/include/endian.h b/include/endian.h
index c77fab1..1ac0872 100644
--- a/include/endian.h
+++ b/include/endian.h
@@ -1,46 +1,9 @@
 /* Copyright (c) 2025 Quinn
  * Licensed under the MIT Licence. See LICENSE for details */
-
 #ifndef PORTABLE_ENDIAN_H
 #define PORTABLE_ENDIAN_H 1
 
 #if defined(__GNUC__)
-
-/* test for the byteswap header */
-#if __has_include(<byteswap.h>)
-#include <byteswap.h>
-#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
-#define le16toh(x) (x)
-#define le32toh(x) (x)
-#define le64toh(x) (x)
-#define htole16(x) (x)
-#define htole32(x) (x)
-#define htole64(x) (x)
-#define be16toh(x) bswap_16(x)
-#define be32toh(x) bswap_32(x)
-#define be64toh(x) bswap_64(x)
-#define htobe16(x) bswap_16(x)
-#define htobe32(x) bswap_32(x)
-#define htobe64(x) bswap_64(x)
-#elif __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
-#define le16toh(x) bswap_16(x)
-#define le32toh(x) bswap_32(x)
-#define le64toh(x) bswap_64(x)
-#define htole16(x) bswap_16(x)
-#define htole32(x) bswap_32(x)
-#define htole64(x) bswap_64(x)
-#define be16toh(x) (x)
-#define be32toh(x) (x)
-#define be64toh(x) (x)
-#define htobe16(x) (x)
-#define htobe32(x) (x)
-#define htobe64(x) (x)
-#else
-#error machine architecture unsupported! Expected either big-endian or little-endian, make sure to use a compiler which defines __BYTE_ORDER__ (like clang or gcc)
-#endif /* byte order */
-
-/* otherwise, utilise the compiler built-ins */
-#else
 #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
 #define le16toh(x) __uint16_identity(x)
 #define le32toh(x) __uint32_identity(x)
@@ -71,10 +34,7 @@
 #error machine architecture unsupported! Expected either big-endian or little-endian, make sure to use a compiler which defines __BYTE_ORDER__ (like clang or gcc)
 #endif /* byte order */
 
-#endif /* has byteswap.h */
-
 #else
 #error GNU C is unavailable
 #endif /* __GNUC__ */
-
 #endif /* PORTABLE_ENDIAN_H */