1 files changed, 8 insertions, 0 deletions

diff --git a/src/xterm.c b/src/xterm.c
index 37e41d0f34a..0e6ed76eb61 100644
--- a/src/xterm.c
+++ b/src/xterm.c
@@ -10632,6 +10632,14 @@ XTread_socket (sd, bufp, numchars, expected)
                                 || ((unsigned)(orig_keysym) == XK_Num_Lock)
 #endif
 #endif /* not HAVE_X11R5 */
+                                /* The symbols from XK_ISO_Lock to
+                                   XK_ISO_Last_Group_Lock doesn't have real
+                                   modifiers but should be treated similarly
+                                   to Mode_switch by Emacs. */
+#if defined XK_ISO_Lock && defined XK_ISO_Last_Group_Lock
+                                || ((unsigned)(orig_keysym) >=  XK_ISO_Lock
+                                    && (unsigned)(orig_keysym) <= XK_ISO_Last_Group_Lock)
+#endif
                                 ))
                         {
                           if (temp_index == sizeof temp_buffer / sizeof (short))