Index: src/OFFile.m
==================================================================
--- src/OFFile.m
+++ src/OFFile.m
@@ -26,10 +26,15 @@
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <stdarg.h>
+
+/* Work around __block being used by glibc */
+#ifdef __GLIBC__
+# undef __USE_XOPEN
+#endif
 
 #include <unistd.h>
 
 #include <fcntl.h>
 #include <dirent.h>

Index: src/OFProcess.m
==================================================================
--- src/OFProcess.m
+++ src/OFProcess.m
@@ -15,10 +15,15 @@
  */
 
 #include "config.h"
 
 #include <string.h>
+
+/* Work around __block being used by glibc */
+#ifdef __GLIBC__
+# undef __USE_XOPEN
+#endif
 
 #ifndef _WIN32
 # include <unistd.h>
 # include <signal.h>
 # include <sys/wait.h>

Index: src/OFStdIOStream.m
==================================================================
--- src/OFStdIOStream.m
+++ src/OFStdIOStream.m
@@ -13,10 +13,16 @@
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
 
 #include "config.h"
+
+/* Work around __block being used by glibc */
+#include <stdlib.h>	/* include any libc header to get the libc defines */
+#ifdef __GLIBC__
+# undef __USE_XOPEN
+#endif
 
 #include <unistd.h>
 
 #import "OFStdIOStream.h"
 #import "OFDate.h"

Index: src/OFSystemInfo.m
==================================================================
--- src/OFSystemInfo.m
+++ src/OFSystemInfo.m
@@ -15,10 +15,16 @@
  */
 
 #define __NO_EXT_QNX
 
 #include "config.h"
+
+/* Work around __block being used by glibc */
+#include <stdlib.h>	/* include any libc header to get the libc defines */
+#ifdef __GLIBC__
+# undef __USE_XOPEN
+#endif
 
 #include <unistd.h>
 
 #import "OFSystemInfo.h"
 #import "OFString.h"

Index: src/OFThread.m
==================================================================
--- src/OFThread.m
+++ src/OFThread.m
@@ -20,10 +20,15 @@
 #include "config.h"
 
 #include <stdlib.h>
 #include <math.h>
 #include <time.h>
+
+/* Work around __block being used by glibc */
+#ifdef __GLIBC__
+# undef __USE_XOPEN
+#endif
 
 #ifndef _WIN32
 # include <unistd.h>
 #endif
 

Index: src/socket_helpers.h
==================================================================
--- src/socket_helpers.h
+++ src/socket_helpers.h
@@ -11,10 +11,15 @@
  * Alternatively, it may be distributed under the terms of the GNU General
  * Public License, either version 2 or 3, which can be found in the file
  * LICENSE.GPLv2 or LICENSE.GPLv3 respectively included in the packaging of this
  * file.
  */
+
+/* Work around __block being used by glibc */
+#ifdef __GLIBC__
+# undef __USE_XOPEN
+#endif
 
 #include <unistd.h>
 
 #ifdef HAVE_ARPA_INET_H
 # include <arpa/inet.h>