diff --git a/arch/aarch64/makecontext.c b/arch/aarch64/makecontext.c
index f0f5a9e..f6823cf 100644
--- a/arch/aarch64/makecontext.c
+++ b/arch/aarch64/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/arm/makecontext.c b/arch/arm/makecontext.c
index bcfb6cf..b137a16 100644
--- a/arch/arm/makecontext.c
+++ b/arch/arm/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/m68k/makecontext.c b/arch/m68k/makecontext.c
index 62ad05f..c1a38e2 100644
--- a/arch/m68k/makecontext.c
+++ b/arch/m68k/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/ppc/makecontext.c b/arch/ppc/makecontext.c
index f7fef69..1b82038 100644
--- a/arch/ppc/makecontext.c
+++ b/arch/ppc/makecontext.c
@@ -11,9 +11,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdarg.h>
 #include <stdint.h>
 
diff --git a/arch/ppc64/makecontext.c b/arch/ppc64/makecontext.c
index 8ec0e45..15ddbf9 100644
--- a/arch/ppc64/makecontext.c
+++ b/arch/ppc64/makecontext.c
@@ -11,9 +11,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stdarg.h>
 #include <stdint.h>
 
diff --git a/arch/riscv32/makecontext.c b/arch/riscv32/makecontext.c
index 044928f..9a43ef4 100644
--- a/arch/riscv32/makecontext.c
+++ b/arch/riscv32/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/riscv64/makecontext.c b/arch/riscv64/makecontext.c
index 044928f..9a43ef4 100644
--- a/arch/riscv64/makecontext.c
+++ b/arch/riscv64/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/s390x/makecontext.c b/arch/s390x/makecontext.c
index 74420cb..22ce252 100644
--- a/arch/s390x/makecontext.c
+++ b/arch/s390x/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/sh/makecontext.c b/arch/sh/makecontext.c
index 0b7c877..7e28e2a 100644
--- a/arch/sh/makecontext.c
+++ b/arch/sh/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/x86/makecontext.c b/arch/x86/makecontext.c
index 938b08d..2f81389 100644
--- a/arch/x86/makecontext.c
+++ b/arch/x86/makecontext.c
@@ -11,9 +11,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>
diff --git a/arch/x86_64/makecontext.c b/arch/x86_64/makecontext.c
index b91e75c..cba9cb1 100644
--- a/arch/x86_64/makecontext.c
+++ b/arch/x86_64/makecontext.c
@@ -10,9 +10,6 @@
  * from the use of this software.
  */
 
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
 #include <stddef.h>
 #include <stdarg.h>
 #include <string.h>