diff --git a/libc/kernel/common/linux/tty.h b/libc/kernel/common/linux/tty.h
index b28791c..b1f2eab 100644
--- a/libc/kernel/common/linux/tty.h
+++ b/libc/kernel/common/linux/tty.h
@@ -12,4 +12,6 @@
 #ifndef _LINUX_TTY_H
 #define _LINUX_TTY_H
 
+#define N_CAIF 20  
+
 #endif