diff --git a/roles/osm-vector-maps/templates/iiab-update-map b/roles/osm-vector-maps/templates/iiab-update-map
index 8221ae56d..62ad5b2a1 100755
--- a/roles/osm-vector-maps/templates/iiab-update-map
+++ b/roles/osm-vector-maps/templates/iiab-update-map
@@ -125,7 +125,7 @@ def write_vector_map_idx(installed_maps):
       idx_dict[item]['region'] = region
       idx_dict[item]['language'] = map_dict['perma_ref'][:2]
 
-   with open(vector_map_idx_dir + 'vector-map-idx.json','w') as idx:
+   with open(vector_map_idx_dir + '/vector-map-idx.json','w') as idx:
       idx.write(json.dumps(idx_dict,indent=2))
 
 def create_menu_def(region,default_name,intended_use='map'):