diff --git a/Source/Apps/FDU/FDU.asm b/Source/Apps/FDU/FDU.asm
index c27cf356..da176f06 100644
--- a/Source/Apps/FDU/FDU.asm
+++ b/Source/Apps/FDU/FDU.asm
@@ -2168,7 +2168,7 @@ FSST_COUNT	.EQU	(($ - FSST) / FSST_ENTSIZ)	; # ENTRIES IN TABLE
 ;
 FCP_CMD		.DB	000H	; INPUT: COMMAND CODE
 FCP_BUFLEN	.DB	00H
-FCP_BUF		.DS	10H
+FCP_BUF		.FILL	10H
 FCP_BUFSIZ	.EQU	$-FCP_BUF
 FCP_XFRCNT	.DW	00H	; BYTES TRANSFERRED DURING COMMAND PHASE	
 ;
@@ -2182,7 +2182,7 @@ FXP_BC		.DW	00H	; LAST VALUE OF REG BC RECORDED DURING EXECUTION
 FXP_DE		.DW	00H	; LAST VALUE OF REG DE RECORDED DURING EXECUTION
 FXP_HL		.DW	00H	; LAST VALUE OF REG HL RECORDED DURING EXECUTION
 FXP_BUFLEN	.DB	00H
-FXP_BUF		.DS	50H	; USED FOR CERTAIN EXEC ROUTINES (FORMAT TRACK)
+FXP_BUF		.FILL	50H	; USED FOR CERTAIN EXEC ROUTINES (FORMAT TRACK)
 FXP_BUFSIZ	.EQU	$-FXP_BUF
 ;
 ; FDC STATUS