4 files changed, 10 insertions, 4 deletions

diff --git a/src/unexmacosx.c b/src/unexmacosx.c
index 2ba67df8bc9..185a9d1f62b 100644
--- a/src/unexmacosx.c
+++ b/src/unexmacosx.c
@@ -85,11 +85,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    be changed accordingly.
 */
 
-/* Make symbols like LLONG_WIDTH visible when the Gnulib <limits.h>
-   is included before <config.h>.  */
-#ifndef _GNU_SOURCE
+/* Enable GNU extensions in gnulib replacement headers.  */
 #define _GNU_SOURCE 1
-#endif
 
 /* config.h #define:s malloc/realloc/free and then includes stdlib.h.
    We want the undefined versions, but if config.h includes stdlib.h
diff --git a/src/w32.c b/src/w32.c
index 1db34260978..6cb8e748bd5 100644
--- a/src/w32.c
+++ b/src/w32.c
@@ -21,6 +21,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    Geoff Voelker (voelker@cs.washington.edu)                         7-29-94
 */
 
+/* Enable GNU extensions in gnulib replacement headers.  */
+#define _GNU_SOURCE 1
+
 #include <mingw_time.h>
 #include <stddef.h> /* for offsetof */
 #include <stdlib.h>
diff --git a/src/w32notify.c b/src/w32notify.c
index d4a113aaa4d..15e8a86cf17 100644
--- a/src/w32notify.c
+++ b/src/w32notify.c
@@ -81,6 +81,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
    thread to exit.  The main thread waits for some time for the worker
    thread to exit, and if it doesn't, terminates it forcibly.  */
 
+/* Enable GNU extensions in gnulib replacement headers.  */
+#define _GNU_SOURCE 1
+
 #include <stddef.h>
 #include <errno.h>
 
diff --git a/src/w32proc.c b/src/w32proc.c
index 90cef3231c8..e23b1b3563c 100644
--- a/src/w32proc.c
+++ b/src/w32proc.c
@@ -22,6 +22,9 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
      Adapted from alarm.c by Tim Fleehart
 */
 
+/* Enable GNU extensions in gnulib replacement headers.  */
+#define _GNU_SOURCE 1
+
 #include <mingw_time.h>
 #include <stdio.h>
 #include <stdlib.h>