diff --git a/configure b/configure
index 9a492b7197e..9e369e943f9 100755
--- a/configure
+++ b/configure
@@ -9111,6 +9111,9 @@ fi
     ;;
 
   linux-android*)
+
+$as_echo "#define _GNU_SOURCE 1" >>confdefs.h
+
     DLLFLAGS="$DLLFLAGS -fPIC"
     LDDLLFLAGS="-fPIC"
     LDEXECFLAGS="-Wl,-pie"
@@ -9290,6 +9293,9 @@ fi
     ;;
 
   *)
+
+$as_echo "#define _GNU_SOURCE 1" >>confdefs.h
+
     case $host_cpu in
       *i[3456789]86*)
         DLLFLAGS="$DLLFLAGS -fno-PIC"
@@ -18424,7 +18430,6 @@ if ${wine_cv_have_sched_setaffinity+:} false; then :
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#define _GNU_SOURCE
 #include <sched.h>
 int
 main ()
@@ -19029,7 +19034,6 @@ fi
 
 
 ac_fn_c_check_member "$LINENO" "struct in6_pktinfo" "ipi6_addr" "ac_cv_member_struct_in6_pktinfo_ipi6_addr" "#ifdef HAVE_NETINET_IN_H
-#define _GNU_SOURCE
 #include <netinet/in.h>
 #endif
 "
@@ -19198,7 +19202,6 @@ if ${ac_cv_have_isfinite+:} false; then :
 else
   cat confdefs.h - <<_ACEOF >conftest.$ac_ext
 /* end confdefs.h.  */
-#define _GNU_SOURCE
 #include <math.h>
 int
 main ()
diff --git a/configure.ac b/configure.ac
index a157c948fec..7afe8285073 100644
--- a/configure.ac
+++ b/configure.ac
@@ -861,6 +861,7 @@ case $host_os in
     ;;
 
   linux-android*)
+    AC_DEFINE(_GNU_SOURCE,1,[Define to 1 to enable GNU extensions on Linux])
     DLLFLAGS="$DLLFLAGS -fPIC"
     LDDLLFLAGS="-fPIC"
     LDEXECFLAGS="-Wl,-pie"
@@ -884,6 +885,7 @@ case $host_os in
     ;;
 
   *)
+    AC_DEFINE(_GNU_SOURCE,1,[Define to 1 to enable GNU extensions on Linux])
     case $host_cpu in
       *i[[3456789]]86*)
         DLLFLAGS="$DLLFLAGS -fno-PIC"
@@ -2217,8 +2219,7 @@ WINE_NOTICE_WITH(ldap,[test "x$LDAP_LIBS" = "x"],
 
 AC_CACHE_CHECK([for sched_setaffinity],wine_cv_have_sched_setaffinity,
                 AC_LINK_IFELSE([AC_LANG_PROGRAM(
-[[#define _GNU_SOURCE
-#include <sched.h>]], [[sched_setaffinity(0, 0, 0);]])],[wine_cv_have_sched_setaffinity=yes],[wine_cv_have_sched_setaffinity=no]))
+[[#include <sched.h>]], [[sched_setaffinity(0, 0, 0);]])],[wine_cv_have_sched_setaffinity=yes],[wine_cv_have_sched_setaffinity=no]))
 if test "$wine_cv_have_sched_setaffinity" = "yes"
 then
   AC_DEFINE(HAVE_SCHED_SETAFFINITY, 1, [Define to 1 if you have the `sched_setaffinity' function.])
@@ -2438,7 +2439,6 @@ AC_CHECK_MEMBERS([struct icmpstat.icps_outhist],,,
 dnl Check for struct in6_pktinfo
 AC_CHECK_MEMBERS([struct in6_pktinfo.ipi6_addr],,,
 [#ifdef HAVE_NETINET_IN_H
-#define _GNU_SOURCE
 #include <netinet/in.h>
 #endif])
 
@@ -2524,8 +2524,7 @@ dnl Check for isfinite
 ac_save_LIBS="$LIBS"
 LIBS="$LIBS -lm"
 AC_CACHE_CHECK([for isfinite], ac_cv_have_isfinite,
-               AC_LINK_IFELSE([AC_LANG_PROGRAM([[#define _GNU_SOURCE
-#include <math.h>]], [[float f = 0.0; return isfinite(f)]])],[ac_cv_have_isfinite="yes"],[ac_cv_have_isfinite="no"]))
+               AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <math.h>]], [[float f = 0.0; return isfinite(f)]])],[ac_cv_have_isfinite="yes"],[ac_cv_have_isfinite="no"]))
 if test "$ac_cv_have_isfinite" = "yes"
 then
     AC_DEFINE(HAVE_ISFINITE, 1, [Define to 1 if you have the `isfinite' function.])
diff --git a/dlls/ntdll/unix/socket.c b/dlls/ntdll/unix/socket.c
index 480d8b4f490..2e79b9baa0f 100644
--- a/dlls/ntdll/unix/socket.c
+++ b/dlls/ntdll/unix/socket.c
@@ -23,7 +23,6 @@
 #endif
 
 #include "config.h"
-#define _GNU_SOURCE /* for struct in6_pktinfo */
 #include <errno.h>
 #include <sys/types.h>
 #include <unistd.h>
diff --git a/dlls/winealsa.drv/mmdevdrv.c b/dlls/winealsa.drv/mmdevdrv.c
index 5f7d277ce9a..7f25cdcce1b 100644
--- a/dlls/winealsa.drv/mmdevdrv.c
+++ b/dlls/winealsa.drv/mmdevdrv.c
@@ -22,7 +22,6 @@
 #include "config.h"
 
 #include <stdarg.h>
-#define _GNU_SOURCE
 #include <stdio.h>
 #include <math.h>
 
diff --git a/include/config.h.in b/include/config.h.in
index e975ca8a55d..51fbd3c9cae 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -1105,6 +1105,9 @@
 /* Number of bits in a file offset, on hosts where this is settable. */
 #undef _FILE_OFFSET_BITS
 
+/* Define to 1 to enable GNU extensions on Linux */
+#undef _GNU_SOURCE
+
 /* Define for large files, on AIX-style hosts. */
 #undef _LARGE_FILES
 
diff --git a/include/wine/port.h b/include/wine/port.h
index 410fa670757..d162c79d9f5 100644
--- a/include/wine/port.h
+++ b/include/wine/port.h
@@ -29,9 +29,6 @@
 # error You must include port.h before all other headers
 #endif
 
-#ifndef _GNU_SOURCE
-# define _GNU_SOURCE  /* for pread/pwrite, isfinite */
-#endif
 #include <fcntl.h>
 #include <math.h>
 #include <sys/types.h>
diff --git a/server/thread.c b/server/thread.c
index 90f3c5492f8..7118f29bf67 100644
--- a/server/thread.c
+++ b/server/thread.c
@@ -20,7 +20,6 @@
 
 #include "config.h"
 
-#define _GNU_SOURCE /* sched_affinity */
 #include <assert.h>
 #include <errno.h>
 #include <fcntl.h>