diff -upr mlterm-3.9.1.org/uitoolkit/ui_screen.c mlterm-3.9.1.mod/uitoolkit/ui_screen.c
--- mlterm-3.9.1.org/uitoolkit/ui_screen.c	2020-11-08 21:57:31.000000000 +0900
+++ mlterm-3.9.1.mod/uitoolkit/ui_screen.c	2021-02-14 19:19:05.164651000 +0900
@@ -1962,19 +1962,19 @@ static int shortcut_match(ui_screen_t *s
 
   if (vt_term_is_backscrolling(screen->term)) {
 #if 1
-    if (ksym == 'u' || ksym == XK_Prior || ksym == XK_KP_Prior) {
+    if (ksym == XK_Prior || ksym == XK_KP_Prior) {
       bs_half_page_downward(screen);
 
       return 1;
-    } else if (ksym == 'd' || ksym == XK_Next || ksym == XK_KP_Next) {
+    } else if (ksym == XK_Next || ksym == XK_KP_Next) {
       bs_half_page_upward(screen);
 
       return 1;
-    } else if (ksym == 'k' || ksym == XK_Up || ksym == XK_KP_Up) {
+    } else if (ksym == XK_Up || ksym == XK_KP_Up) {
       bs_scroll_downward(screen, 1, 1);
 
       return 1;
-    } else if (ksym == 'j' || ksym == XK_Down || ksym == XK_KP_Down) {
+    } else if (ksym == XK_Down || ksym == XK_KP_Down) {
       bs_scroll_upward(screen, 1, 1);
 
       return 1;