diff --git a/include/sched.h b/include/sched.h
index 674bad7f..7e470d3a 100644
--- a/include/sched.h
+++ b/include/sched.h
@@ -49,6 +49,7 @@ int     sched_yield(void);
 #define CLONE_FS	0x00000200
 #define CLONE_FILES	0x00000400
 #define CLONE_SIGHAND	0x00000800
+#define CLONE_PIDFD	0x00001000
 #define CLONE_PTRACE	0x00002000
 #define CLONE_VFORK	0x00004000
 #define CLONE_PARENT	0x00008000