diff --git a/common/hooks/post-install/06-strip-and-debug-pkgs.sh b/common/hooks/post-install/06-strip-and-debug-pkgs.sh
index 4a703c8007..075461304c 100644
--- a/common/hooks/post-install/06-strip-and-debug-pkgs.sh
+++ b/common/hooks/post-install/06-strip-and-debug-pkgs.sh
@@ -7,7 +7,7 @@ make_debug() {
 
 	[ -n "$nodebug" ] && return 0
 
-	dname=$(echo "$(dirname $1)"|sed -e "s|${PKGDESTDIR}||g")
+	dname=${1%/*}/ ; dname=${dname#$PKGDESTDIR}
 	fname="${1##*/}"
 	dbgfile="${dname}/${fname}"
 
@@ -26,7 +26,7 @@ attach_debug() {
 
 	[ -n "$nodebug" ] && return 0
 
-	dname=$(echo "$(dirname $1)"|sed -e "s|${PKGDESTDIR}||g")
+	dname=${1%/*}/ ; dname=${dname#$PKGDESTDIR}
 	fname="${1##*/}"
 	dbgfile="${dname}/${fname}"