diff --git a/kernel/descriptor.cpp b/kernel/descriptor.cpp
index c198b79e..dd4dd38d 100644
--- a/kernel/descriptor.cpp
+++ b/kernel/descriptor.cpp
@@ -52,7 +52,7 @@ const int ACCESS_FLAGS = O_READ | O_WRITE | O_EXEC | O_SEARCH;
 
 // Flags that only make sense at open time.
 const int OPEN_FLAGS = O_CREATE | O_DIRECTORY | O_EXCL | O_TRUNC | O_NOFOLLOW |
-                       O_SYMLINK_NOFOLLOW | O_NOCTTY;
+                       O_SYMLINK_NOFOLLOW | O_NOCTTY | O_TTY_INIT;
 
 // Flags that only make sense for descriptors.
 const int DESCRIPTOR_FLAGS = O_APPEND | O_NONBLOCK;
diff --git a/kernel/include/sortix/fcntl.h b/kernel/include/sortix/fcntl.h
index 270c63b0..8d141a8f 100644
--- a/kernel/include/sortix/fcntl.h
+++ b/kernel/include/sortix/fcntl.h
@@ -46,6 +46,7 @@ __BEGIN_DECLS
 #define O_NOFOLLOW (1<<12)
 #define O_SYMLINK_NOFOLLOW (1<<13)
 #define O_NOCTTY (1<<14)
+#define O_TTY_INIT (1<<15)
 
 #define FD_CLOEXEC (1<<0)
 #define FD_CLOFORK (1<<1)