diff --git a/borg_exporter.sh b/borg_exporter.sh
index 3c9b9d1..30c1a07 100755
--- a/borg_exporter.sh
+++ b/borg_exporter.sh
@@ -9,7 +9,7 @@ PROM_FILE=$TEXTFILE_COLLECTOR_DIR/backup.prom
 TMP_FILE=$PROM_FILE.$$
 
 if [[ -n "$REPO_BASE" ]] ; then
-  REPOS+=("$REPO_BASE")
+  REPO_BASES+=("$REPO_BASE")
 fi
 
 for repo_base in "${REPO_BASES[@]}"; do