diff --git a/fiber.c b/fiber.c
index 38a293df..50af4a72 100644
--- a/fiber.c
+++ b/fiber.c
@@ -1,5 +1,6 @@
 #define LIBCO_C
 #include "libco.h"
+#include "settings.h"
 
 #define WINVER 0x0400
 #define _WIN32_WINNT 0x0400
diff --git a/sjlj.c b/sjlj.c
index 4d5017f5..1d0cb59a 100644
--- a/sjlj.c
+++ b/sjlj.c
@@ -7,6 +7,7 @@
 #include "libco.h"
 #include "settings.h"
 
+#define _BSD_SOURCE
 #define _XOPEN_SOURCE 500
 #include <stdlib.h>
 #include <signal.h>
diff --git a/ucontext.c b/ucontext.c
index f4527bfb..9ba47c88 100644
--- a/ucontext.c
+++ b/ucontext.c
@@ -12,8 +12,10 @@
 
 #define LIBCO_C
 #include "libco.h"
+#include "settings.h"
 
 #define _BSD_SOURCE
+#define _XOPEN_SOURCE 500
 #include <stdlib.h>
 #include <ucontext.h>