diff --git a/newlib/ChangeLog b/newlib/ChangeLog
index 1e656d831..f95dad423 100644
--- a/newlib/ChangeLog
+++ b/newlib/ChangeLog
@@ -1,3 +1,8 @@
+2015-02-24  Jon TURNEY  <jon.turney@dronecode.org.uk>
+
+	* libc/include/sys/cdefs.h (_GNU_SOURCE): Move check so it has an
+	effect when _XOPEN_SOURCE is also defined.
+
 2015-02-17  Hale Wang  <hale.wang@arm.com>
 
 	* libc/machine/arm/aeabi_memclr.c: New file to support
diff --git a/newlib/libc/include/sys/cdefs.h b/newlib/libc/include/sys/cdefs.h
index a5e613c63..f1747d0f1 100644
--- a/newlib/libc/include/sys/cdefs.h
+++ b/newlib/libc/include/sys/cdefs.h
@@ -606,6 +606,14 @@
  * Our macros begin with two underscores to avoid namespace screwage.
  */
 
+/* Deal with _GNU_SOURCE, which implies everything and the kitchen sink */
+#ifdef _GNU_SOURCE
+#undef _XOPEN_SOURCE
+#define	_XOPEN_SOURCE		700
+#define	__BSD_VISIBLE		1
+#define	__GNU_VISIBLE		1
+#endif
+
 /* Deal with IEEE Std. 1003.1-1990, in which _POSIX_C_SOURCE == 1. */
 #if defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE == 1
 #undef _POSIX_C_SOURCE		/* Probably illegal, but beyond caring now. */
@@ -693,12 +701,6 @@
 #define	__XSI_VISIBLE		0
 #define	__BSD_VISIBLE		0
 #define	__ISO_C_VISIBLE		2011
-#elif defined(_GNU_SOURCE)	/* Everything and the kitchen sink. */
-#define	__POSIX_VISIBLE		200809
-#define	__XSI_VISIBLE		700
-#define	__BSD_VISIBLE		1
-#define	__ISO_C_VISIBLE		2011
-#define	__GNU_VISIBLE		1
 #else				/* Default: everything except __GNU_VISIBLE. */
 #define	__POSIX_VISIBLE		200809
 #define	__XSI_VISIBLE		700