diff --git a/ChangeLog b/ChangeLog
index 03be98bcb..a3deb7c10 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2008-10-01  Tor Lillqvist  <tml@novell.com>
+
+	* gtk/gtkscalebutton.c: Don't #define _GNU_SOURCE on Windows as it
+	confuses newest mingw headers.
+
 2008-10-01  Tor Lillqvist  <tml@novell.com>
 
 	* gdk/win32/gdkkeys-win32.c (gdk_keymap_get_caps_lock_state):
diff --git a/gtk/gtkscalebutton.c b/gtk/gtkscalebutton.c
index ac491e6b7..c70573bc9 100644
--- a/gtk/gtkscalebutton.c
+++ b/gtk/gtkscalebutton.c
@@ -35,7 +35,9 @@
 
 #include "config.h"
 
+#ifndef _WIN32
 #define _GNU_SOURCE
+#endif
 #include <math.h>
 #include <stdlib.h>
 #include <string.h>