diff --git a/bin/stacks b/bin/stacks
index d694fbb..4a62183 100755
--- a/bin/stacks
+++ b/bin/stacks
@@ -475,6 +475,7 @@ Type=oneshot
 User=root
 ExecStart=${_self} update run
 Environment=HOME=/root
+Environment=STACKS_DIR=${STACKS_DIR}
 EOF
       cat > /etc/systemd/system/stacks-update.timer << 'EOF'
 [Unit]
@@ -632,6 +633,7 @@ Type=oneshot
 User=root
 ExecStart=${_self} backup run
 Environment=HOME=/root
+Environment=STACKS_DIR=${STACKS_DIR}
 EOF
       cat > /etc/systemd/system/stacks-backup.timer << 'EOF'
 [Unit]