diff --git a/Source/HBIOS/sd.asm b/Source/HBIOS/sd.asm
index 71812ce6..80a3c0ad 100644
--- a/Source/HBIOS/sd.asm
+++ b/Source/HBIOS/sd.asm
@@ -384,7 +384,7 @@ SD_CS0		.EQU	%00000100	; SELECT
 SD_DI		.EQU	%00000001	; DATA IN (CARD <- CPU) MOSI
 SD_DO		.EQU	%00000001	; DATA OUT (CARD -> CPU) MISO
 SD_CINIT	.EQU	FALSE		; INITIALIZE OUTPUT PORT
-SD_INVCS	.EQU	TRUE		; INVERT CS
+SD_INVCS	.EQU	FALSE		; INVERT CS
 		DEVECHO	"Z80R"
 #ENDIF
 ;