diff --git a/Source/HBIOS/sd.asm b/Source/HBIOS/sd.asm
index a45738ca..16c589d9 100644
--- a/Source/HBIOS/sd.asm
+++ b/Source/HBIOS/sd.asm
@@ -1045,7 +1045,7 @@ SD_INITCARD5:
 	CALL	SD_WAITTX		; MAKE SURE WE ARE DONE SENDING
 	CALL	DLY32			; WAIT A BIT MORE FOR FINAL BIT
 	XOR	A			; ZERO MEANS MAX SPEED
-	OUT	(Z180_CNTR),A		; NOW SET CSIO PORT
+	OUT0	(Z180_CNTR),A		; NOW SET CSIO PORT
 #ENDIF
 ;
 	; ISSUE SEND_CSD (TO DERIVE CARD CAPACITY)