diff --git a/tools/add_missing_uuid.py b/tools/add_missing_uuid.py
index a556216..229a9b3 100644
--- a/tools/add_missing_uuid.py
+++ b/tools/add_missing_uuid.py
@@ -6,10 +6,10 @@ import argparse
 import uuid
 
 parser = argparse.ArgumentParser(description='Add missing uuids in clusters')
-parser.add_argument("-f", "--filename", required=True, help="nameof the cluster (without .json)")
+parser.add_argument("-f", "--filename", required=True, help="name of the cluster")
 args = parser.parse_args()
 
-with open(args.filename+'.json') as json_file:
+with open(args.filename) as json_file:
     data = json.load(json_file)
     json_file.close()
 
@@ -17,5 +17,5 @@ with open(args.filename+'.json') as json_file:
         if 'uuid' not in value:
             value['uuid'] = str(uuid.uuid4())
 
-with open(args.filename+'.json', 'w') as json_file:
+with open(args.filename, 'w') as json_file:
     json.dump(data, json_file, indent=4)