diff -pNaru5 a/driver/2.6.27/dgrp_tty.c b/driver/2.6.27/dgrp_tty.c
--- a/driver/2.6.27/dgrp_tty.c	2023-01-03 01:50:17.756406551 -0500
+++ b/driver/2.6.27/dgrp_tty.c	2023-01-03 01:50:45.197687357 -0500
@@ -60,11 +60,15 @@
 #else
 #include <linux/sched/signal.h>	/* For in_egroup_p() and signal_pending() */
 #endif
 
 #include <linux/serial.h>
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6,1,0)
 #include <linux/termios.h>
+#else
+#include <linux/termios_internal.h>
+#endif
 #include <linux/delay.h>
 #if LINUX_VERSION_CODE >= KERNEL_VERSION(3,10,0)
 #include <linux/slab.h>
 #endif