Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -623,11 +623,15 @@
 
 	AC_CHECK_HEADER(sys/socket.h, [
 		AC_DEFINE(OF_HAVE_SYS_SOCKET_H, 1,
 			[Whether we have sys/socket.h])
 	])
-	AC_CHECK_HEADERS([netinet/in.h arpa/inet.h netdb.h])
+	AC_CHECK_HEADERS(netinet/in.h, [
+		AC_DEFINE(OF_HAVE_NETINET_IN_H, 1,
+			[Whether we have netinet/in.h])
+	])
+	AC_CHECK_HEADERS([arpa/inet.h netdb.h])
 
 	AC_CHECK_FUNC(kqueue, [
 		AC_DEFINE(HAVE_KQUEUE, 1, [Whether we have kqueue])
 		AC_SUBST(OFKERNELEVENTOBSERVER_KQUEUE_M,
 			"OFKernelEventObserver_kqueue.m")

Index: src/objfw-defs.h.in
==================================================================
--- src/objfw-defs.h.in
+++ src/objfw-defs.h.in
@@ -9,10 +9,11 @@
 #undef OF_HAVE_FILES
 #undef OF_HAVE_FORWARDING_TARGET_FOR_SELECTOR
 #undef OF_HAVE_GCC_ATOMIC_OPS
 #undef OF_HAVE_LINK
 #undef OF_HAVE_MAX_ALIGN_T
+#undef OF_HAVE_NETINET_IN_H
 #undef OF_HAVE_OSATOMIC
 #undef OF_HAVE_OSATOMIC_64
 #undef OF_HAVE_PIPE
 #undef OF_HAVE_PLUGINS
 #undef OF_HAVE_PROCESSES

Index: src/socket.h
==================================================================
--- src/socket.h
+++ src/socket.h
@@ -22,10 +22,13 @@
 
 #include <stdbool.h>
 
 #ifdef OF_HAVE_SYS_SOCKET_H
 # include <sys/socket.h>
+#endif
+#ifdef OF_HAVE_NETINET_IN_H
+# include <netinet/in.h>
 #endif
 
 #ifdef _WIN32
 # ifdef __MINGW32__
 #  include <_mingw.h>

Index: src/socket_helpers.h
==================================================================
--- src/socket_helpers.h
+++ src/socket_helpers.h
@@ -14,13 +14,10 @@
  * file.
  */
 
 #include <unistd.h>
 
-#ifdef HAVE_NETINET_IN_H
-# include <netinet/in.h>
-#endif
 #ifdef HAVE_ARPA_INET_H
 # include <arpa/inet.h>
 #endif
 #ifdef HAVE_NETDB_H
 # include <netdb.h>