Index: configure.ac
==================================================================
--- configure.ac
+++ configure.ac
@@ -725,28 +725,28 @@
 
 	AC_CHECK_TYPE(off64_t, [
 		AC_DEFINE(OF_HAVE_OFF64_T, 1, [Whether we have off64_t])
 	])
 
-	AC_CHECK_FUNCS(readdir_r)
-])
-
-AC_CHECK_FUNCS([sysconf gmtime_r localtime_r nanosleep lstat])
-
-AC_CHECK_HEADERS([pwd.h grp.h])
-AC_CHECK_FUNC(chmod, [
-	AC_DEFINE(OF_HAVE_CHMOD, 1, [Whether we have chmod()])
-])
-AC_CHECK_FUNC(chown, [
-	AC_DEFINE(OF_HAVE_CHOWN, 1, [Whether we have chown()])
-])
-AC_CHECK_FUNC(link, [
-	AC_DEFINE(OF_HAVE_LINK, 1, [Whether we have link()])
-])
-AC_CHECK_FUNC(symlink, [
-	AC_DEFINE(OF_HAVE_SYMLINK, 1, [Whether we have symlink()])
-])
+	AC_CHECK_HEADERS([pwd.h grp.h])
+	AC_CHECK_FUNC(chmod, [
+		AC_DEFINE(OF_HAVE_CHMOD, 1, [Whether we have chmod()])
+	])
+	AC_CHECK_FUNC(chown, [
+		AC_DEFINE(OF_HAVE_CHOWN, 1, [Whether we have chown()])
+	])
+	AC_CHECK_FUNC(link, [
+		AC_DEFINE(OF_HAVE_LINK, 1, [Whether we have link()])
+	])
+	AC_CHECK_FUNC(symlink, [
+		AC_DEFINE(OF_HAVE_SYMLINK, 1, [Whether we have symlink()])
+	])
+	AC_CHECK_FUNCS([lstat readdir_r])
+])
+
+AC_CHECK_FUNCS([sysconf gmtime_r localtime_r nanosleep fcntl])
+
 AC_CHECK_FUNC(pipe, [
 	AC_DEFINE(OF_HAVE_PIPE, 1, [Whether we have pipe()])
 ])
 
 AC_ARG_ENABLE(sockets,
@@ -775,11 +775,11 @@
 		AC_DEFINE(OF_HAVE_NETINET_TCP_H, 1,
 			[Whether we have netinet/tcp.h])
 	])
 	AC_CHECK_HEADERS([arpa/inet.h netdb.h])
 
-	AC_CHECK_FUNCS([fcntl paccept accept4])
+	AC_CHECK_FUNCS([paccept accept4])
 
 	AC_CHECK_FUNC(kqueue, [
 		AC_DEFINE(HAVE_KQUEUE, 1, [Whether we have kqueue])
 		AC_SUBST(OFKERNELEVENTOBSERVER_KQUEUE_M,
 			"OFKernelEventObserver_kqueue.m")

Index: src/OFFile.m
==================================================================
--- src/OFFile.m
+++ src/OFFile.m
@@ -35,12 +35,12 @@
 # undef __USE_XOPEN
 #endif
 
 #include <unistd.h>
 
-#include <fcntl.h>
 #include <dirent.h>
+#include <fcntl.h>
 
 #ifdef HAVE_PWD_H
 # include <pwd.h>
 #endif
 #ifdef HAVE_GRP_H

Index: src/OFStream.m
==================================================================
--- src/OFStream.m
+++ src/OFStream.m
@@ -1472,11 +1472,11 @@
 	return _blocking;
 }
 
 - (void)setBlocking: (bool)enable
 {
-#ifndef _WIN32
+#ifdef HAVE_FCNTL
 	bool readImplemented = false, writeImplemented = false;
 
 	@try {
 		int readFlags;
 

Index: src/OFTCPSocket.m
==================================================================
--- src/OFTCPSocket.m
+++ src/OFTCPSocket.m
@@ -23,10 +23,12 @@
 #include <assert.h>
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
+
+#include <fcntl.h>
 
 #import "OFTCPSocket.h"
 #import "OFTCPSocket+SOCKS5.h"
 #import "OFString.h"
 #import "OFThread.h"

Index: src/OFUDPSocket.m
==================================================================
--- src/OFUDPSocket.m
+++ src/OFUDPSocket.m
@@ -17,10 +17,12 @@
 #include "config.h"
 
 #include <assert.h>
 #include <errno.h>
 #include <string.h>
+
+#include <fcntl.h>
 
 #import "OFUDPSocket.h"
 #ifdef OF_HAVE_THREADS
 # import "OFThread.h"
 #endif

Index: src/socket.h
==================================================================
--- src/socket.h
+++ src/socket.h
@@ -20,12 +20,10 @@
 # error No sockets available!
 #endif
 
 #include <stdbool.h>
 
-#include <fcntl.h>
-
 #ifdef OF_HAVE_SYS_SOCKET_H
 # include <sys/socket.h>
 #endif
 #ifdef OF_HAVE_NETINET_IN_H
 # include <netinet/in.h>