diff --git a/libsrc/geos-common/disk/calcblksfree.s b/libsrc/geos-common/disk/calcblksfree.s
index 520c8ca61..5d7b98aba 100644
--- a/libsrc/geos-common/disk/calcblksfree.s
+++ b/libsrc/geos-common/disk/calcblksfree.s
@@ -13,6 +13,10 @@
             .include "geossym.inc"
         
 _CalcBlksFree:
+        lda #<curDirHead
+        ldx #>curDirHead
+        sta r5L
+        stx r5H
         jsr CalcBlksFree
         stx __oserror
         lda r4L