diff --git a/x11/x11.c b/x11/x11.c
index ffb850b3..a5231061 100644
--- a/x11/x11.c
+++ b/x11/x11.c
@@ -111,6 +111,9 @@ static struct
  {XK_F20,       FALSE,  KEY_F(20),   KEY_F(32),    KEY_F(44),   KEY_F(56)},
  {XK_BackSpace, FALSE,  0x08,        0x08,         CTL_BKSP,    ALT_BKSP},
  {XK_Tab,       FALSE,  0x09,        KEY_BTAB,     CTL_TAB,     ALT_TAB},
+#if defined(XK_ISO_Left_Tab)
+ {XK_ISO_Left_Tab, FALSE, 0x09,      KEY_BTAB,     CTL_TAB,     ALT_TAB},
+#endif
  {XK_Select,    FALSE,  KEY_SELECT,  KEY_SELECT,   KEY_SELECT,  KEY_SELECT},
  {XK_Print,     FALSE,  KEY_PRINT,   KEY_SPRINT,   KEY_PRINT,   KEY_PRINT},
  {XK_Find,      FALSE,  KEY_FIND,    KEY_SFIND,    KEY_FIND,    KEY_FIND},