diff --git a/postgres-docker/backup.sh b/postgres-docker/backup.sh
index c42476bc3..0df92400d 100755
--- a/postgres-docker/backup.sh
+++ b/postgres-docker/backup.sh
@@ -1,3 +1,7 @@
 #!/bin/bash
+if [ -z "$POSTGRES_DB" ]; then
+    echo "Database not specified, defaulting to bookwyrm"
+fi
+BACKUP_DB=${POSTGRES_DB:-bookwyrm}
 filename=backup__$(date +%F)
-pg_dump -U bookwyrm  > /backups/$filename.sql
+pg_dump -U $BACKUP_DB > /backups/$filename.sql