--- include/uapi/linux/libc-compat.h.orig	2015-05-31 15:43:30.635620792 +0200
+++ include/uapi/linux/libc-compat.h	2015-05-31 15:48:08.787163241 +0200
@@ -48,30 +48,27 @@
 #ifndef _UAPI_LIBC_COMPAT_H
 #define _UAPI_LIBC_COMPAT_H
 
-/* We have included glibc headers... */
-#if defined(__GLIBC__)
+#ifndef __KERNEL__ /* we're used from userspace */
 
-/* Coordinate with glibc netinet/in.h header. */
-#if defined(_NETINET_IN_H)
+#ifdef _NETINET_IF_ETHER_H /* musl */
+#define __UAPI_DEF_ETHHDR 0
+#else /* glibc uses __NETINET_IF_ETHER_H, and includes the kernel header. */
+#define __UAPI_DEF_ETHHDR 1
+#endif
+
+/* Coordinate with libc netinet/in.h header. */
+#ifdef _NETINET_IN_H
 
 /* GLIBC headers included first so don't define anything
  * that would already be defined. */
 #define __UAPI_DEF_IN6_ADDR		0
-/* The exception is the in6_addr macros which must be defined
- * if the glibc code didn't define them. This guard matches
- * the guard in glibc/inet/netinet/in.h which defines the
- * additional in6_addr macros e.g. s6_addr16, and s6_addr32. */
-#if defined(__USE_MISC) || defined (__USE_GNU)
 #define __UAPI_DEF_IN6_ADDR_ALT		0
-#else
-#define __UAPI_DEF_IN6_ADDR_ALT		1
-#endif
 #define __UAPI_DEF_SOCKADDR_IN6		0
 #define __UAPI_DEF_IPV6_MREQ		0
 #define __UAPI_DEF_IPPROTO_V6		0
 #define __UAPI_DEF_IPV6_OPTIONS		0
 
-#else
+#else /* defined(_NETINET_IN_H) */
 
 /* Linux headers included first, and we must define everything
  * we need. The expectation is that glibc will check the
@@ -97,7 +94,7 @@
 /* If we did not see any headers from any supported C libraries,
  * or we are being included in the kernel, then define everything
  * that we need. */
-#else /* !defined(__GLIBC__) */
+#else /* __KERNEL__ */
 
 /* Definitions for in6.h */
 #define __UAPI_DEF_IN6_ADDR		1
@@ -110,6 +107,6 @@
 /* Definitions for xattr.h */
 #define __UAPI_DEF_XATTR		1
 
-#endif /* __GLIBC__ */
+#endif /* __KERNEL__ */
 
 #endif /* _UAPI_LIBC_COMPAT_H */