diff --git a/src/mame/machine/zorbakbd.cpp b/src/mame/machine/zorbakbd.cpp
index 496b11ef832..1cb8be7ce20 100644
--- a/src/mame/machine/zorbakbd.cpp
+++ b/src/mame/machine/zorbakbd.cpp
@@ -76,7 +76,7 @@ INPUT_PORTS_START(zorba_keyboard)
 	PORT_BIT( 0x80, IP_ACTIVE_LOW, IPT_KEYBOARD )                           PORT_CODE(KEYCODE_SLASH)      PORT_CHAR('/') PORT_CHAR('?')
 
 	PORT_START("ROW3")
-	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("F4")           PORT_CODE(KEYCODE_F4)         PORT_CHAR(UCHAR_MAMEKEY(F3))
+	PORT_BIT( 0x01, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("F4")           PORT_CODE(KEYCODE_F4)         PORT_CHAR(UCHAR_MAMEKEY(F4))
 	PORT_BIT( 0x02, IP_ACTIVE_LOW, IPT_KEYBOARD ) PORT_NAME("F16")          PORT_CODE(KEYCODE_F16)        PORT_CHAR(UCHAR_MAMEKEY(F16))
 	PORT_BIT( 0x04, IP_ACTIVE_LOW, IPT_KEYBOARD )                           PORT_CODE(KEYCODE_6)          PORT_CHAR('6') PORT_CHAR('^')
 	PORT_BIT( 0x08, IP_ACTIVE_LOW, IPT_UNKNOWN  ) // b7