diff --git a/src/devices/bus/pc_kbd/pcat84.cpp b/src/devices/bus/pc_kbd/pcat84.cpp
index d4d6c4e98de..8a079ad61a5 100644
--- a/src/devices/bus/pc_kbd/pcat84.cpp
+++ b/src/devices/bus/pc_kbd/pcat84.cpp
@@ -236,7 +236,7 @@ INPUT_PORTS_START( ibm_pc_at_84_keyboard )
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_ENTER) PORT_CHAR(13)
 	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_TILDE) PORT_CHAR('`') PORT_CHAR('~')
 	PORT_BIT( 0x10, IP_ACTIVE_LOW, IPT_UNUSED )
-	PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_UNUSED )
+	PORT_BIT( 0x20, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_CODE(KEYCODE_BACKSLASH) PORT_CHAR('\\') PORT_CHAR('|')
 	PORT_BIT( 0x40, IP_ACTIVE_LOW, IPT_UNUSED )
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_UNUSED )