diff --git a/term/sys/linux/print.c b/term/sys/linux/print.c
index c4a909b..97dd094 100644
--- a/term/sys/linux/print.c
+++ b/term/sys/linux/print.c
@@ -1,3 +1,5 @@
+#define _POSIX_C_SOURCE 200809L
+
 #include "../../print.h"
 
 #include <stdio.h>
diff --git a/term/sys/linux/tty.c b/term/sys/linux/tty.c
index a9135a1..2b08f74 100644
--- a/term/sys/linux/tty.c
+++ b/term/sys/linux/tty.c
@@ -1,3 +1,5 @@
+#define _POSIX_C_SOURCE 200809L
+
 #include "../../tty.h"
 
 #include <fx/term/tty.h>