diff -u kterm-6.2.0~/main.c kterm-6.2.0/main.c
--- kterm-6.2.0~/main.c	1996-07-12 14:01:38.000000000 +0900
+++ kterm-6.2.0/main.c	2023-08-15 15:21:56.750366716 +0900
@@ -133,6 +133,7 @@
 #endif
 
 #ifdef linux
+#define USE_TERMIOS
 #define USE_SYSV_TERMIO
 #define USE_SYSV_PGRP
 #define USE_SYSV_UTMP
@@ -1152,7 +1153,9 @@
 
 #ifdef USE_TERMIOS /* { */
 	d_tio.c_cc[VSUSP] = CSUSP;
+#ifdef VDSUSP
 	d_tio.c_cc[VDSUSP] = CDSUSP;
+#endif
 	d_tio.c_cc[VREPRINT] = CRPRNT;
 	d_tio.c_cc[VDISCARD] = CFLUSH;
 	d_tio.c_cc[VWERASE] = CWERASE;
@@ -1293,7 +1296,9 @@
 #endif	/* } TIOCSLTC */
 #ifdef USE_TERMIOS /* { */
 	d_tio.c_cc[VSUSP] = CSUSP;
+#ifdef VDSUSP
 	d_tio.c_cc[VDSUSP] = '\000';
+#endif
 	d_tio.c_cc[VREPRINT] = '\377';
 	d_tio.c_cc[VDISCARD] = '\377';
 	d_tio.c_cc[VWERASE] = '\377';