diff --git a/linux/make_deb.sh b/linux/make_deb.sh
index 5df1f2381..cbbc8a184 100755
--- a/linux/make_deb.sh
+++ b/linux/make_deb.sh
@@ -7,7 +7,7 @@ case "$MACHINE" in
   i386)   ARCHITECTURE=i386;;
 esac
 
-ARTIFACTS=?/artifacts
+ARTIFACTS="${ARTIFACTS:-/artifacts}"
 
 VERSION=`$ARTIFACTS/pandoc --version | awk '{print $2; exit;}'`
 REVISION=${REVISION:-1}
diff --git a/linux/make_tarball.sh b/linux/make_tarball.sh
index 7d465e06e..2a4efe05f 100644
--- a/linux/make_tarball.sh
+++ b/linux/make_tarball.sh
@@ -1,7 +1,7 @@
 set -e
 
 TARGET=pandoc-$VERSION
-ARTIFACTS=?/artifacts
+ARTIFACTS="${ARTIFACTS:-/artifacts}"
 VERSION=`$ARTIFACTS/pandoc --version | awk '{print $2; exit;}'`
 
 cd $ARTIFACTS