diff --git a/bin/bump-version b/bin/bump-version
index f37226570d0b5b2f8644e96249ebefdb6cc40191..0582b9cc7c42f0462761b2f8150ed63bc6d0864c 100755
--- a/bin/bump-version
+++ b/bin/bump-version
@@ -13,8 +13,8 @@ if [ -z "$NEWVER" ] ; then
   NEWVER="$(echo $OLDVER | perl -npe 's/([0-9].[0-9]+)(\.([0-9]+))?/"${1}.".($3+1)/e')"
 fi
 echo "Setting ASDF version to $NEWVER"
-perl -i.bak -npe 's/^(         \(asdf-version "|;;; This is ASDF )[0-9.]+("\)|:)/${1}'"$NEWVER"'${2}/' $ASDFLISP
-perl -i.bak -npe 's/^(  :version ")[0-9.]+(")/${1}'"$NEWVER"'${2}/' $ASDFASD
+perl -npe 's/^(         \(asdf-version "|;;; This is ASDF )[0-9.]+("\)|:)/${1}'"$NEWVER"'${2}/' $ASDFLISP
+perl -npe 's/^(  :version ")[0-9.]+(")/${1}'"$NEWVER"'${2}/' $ASDFASD
 cat<<EOF
 To complete the version change, you may:
 	git add -u