diff --git a/Source/HBIOS/cfg_duo.asm b/Source/HBIOS/cfg_duo.asm
index cccb5c87..afc62ad0 100644
--- a/Source/HBIOS/cfg_duo.asm
+++ b/Source/HBIOS/cfg_duo.asm
@@ -122,7 +122,7 @@ DS7RTCMODE	.EQU	DS7RTCMODE_PCF	; DS7RTC: OPERATING MODE: DS7RTC_[PCF]
 DUARTENABLE	.EQU	FALSE		; DUART: ENABLE 2681/2692 SERIAL DRIVER (DUART.ASM)
 ;
 UARTENABLE	.EQU	TRUE		; UART: ENABLE 8250/16550-LIKE SERIAL DRIVER (UART.ASM)
-UARTOSC		.EQU	1843200		; UART: OSC FREQUENCY IN MHZ
+UARTOSC		.EQU	7372800		; UART: OSC FREQUENCY IN MHZ
 UARTINTS	.EQU	FALSE		; UART: INCLUDE INTERRUPT SUPPORT UNDER IM1/2/3
 UARTCFG		.EQU	DEFSERCFG	; UART: LINE CONFIG FOR UART PORTS
 UARTCASSPD	.EQU	SER_300_8N1	; UART: ECB CASSETTE UART DEFAULT SPEED