diff --git a/README.md b/README.md
index 4108a56..2c6e7ca 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,5 @@
 # Graylog Archiver
-Archives graylog indices to `backup_dir`, keeping the latest ones (`max_indices`).
+Archives graylog indices (`index_prefix`) to `backup_dir`, keeping the latest ones (`max_indices`).
 
 For example, if you have the following indices:
 
@@ -33,6 +33,7 @@ Create a configuration file for graylog archiver `graylog_archiver.json`:
   "elasticsearch": {
     "hosts": "localhost"
   },
+  "index_prefix": "graylog",
   "max_indices": 3,
   "backup_dir": "/srv/backups/elasticsearch/graylog",
   "delete": false
diff --git a/graylog_archiver/cli.py b/graylog_archiver/cli.py
index 58239f7..2d826c4 100644
--- a/graylog_archiver/cli.py
+++ b/graylog_archiver/cli.py
@@ -25,6 +25,7 @@ def main():
 
     archiver = GraylogArchiver(
         es=Elasticsearch(**args.config.get("elasticsearch")),
+        index_prefix=args.config.get("index_prefix"),
         max_indices=args.config.get("max_indices"),
         backup_dir=args.config.get("backup_dir"),
         delete=args.config.get("delete")
diff --git a/graylog_archiver/graylog_archiver.py b/graylog_archiver/graylog_archiver.py
index 1813379..53f09d2 100644
--- a/graylog_archiver/graylog_archiver.py
+++ b/graylog_archiver/graylog_archiver.py
@@ -5,13 +5,14 @@
 
 
 class GraylogArchiver:
-    def __init__(self, es, max_indices, backup_dir, delete=False):
+    def __init__(self, es, index_prefix, max_indices, backup_dir, delete=False):
         self.es = es
+        self.index_prefix = index_prefix
         self.max_indices = max_indices
         self.backup_dir = backup_dir
         self.delete = delete
         self.logger = logs.create_logger()
-        self.graylog = GraylogElasticsearch(es, max_indices, backup_dir)
+        self.graylog = GraylogElasticsearch(es, index_prefix, max_indices, backup_dir)
 
     def archive(self):
         self.logger.info("Indices: %s" % self.graylog.indices())
diff --git a/graylog_archiver/graylog_elasticsearch.py b/graylog_archiver/graylog_elasticsearch.py
index f8d6368..fcfc88e 100644
--- a/graylog_archiver/graylog_elasticsearch.py
+++ b/graylog_archiver/graylog_elasticsearch.py
@@ -15,13 +15,14 @@ def sort_indices(indices):
 
 
 class GraylogElasticsearch:
-    def __init__(self, es, max_indices, backup_dir):
+    def __init__(self, es, index_prefix, max_indices, backup_dir):
         self.es = es
+        self.index_prefix = index_prefix
         self.max_indices = max_indices
         self.backup_dir = backup_dir
 
     def indices(self):
-        return list(self.es.indices.get_mapping().keys())
+        return list(filter(lambda x: x.startswith(self.index_prefix), list(self.es.indices.get_mapping().keys())))
 
     def indices_to_archive(self):
         indices_sorted = sort_indices(self.indices())
diff --git a/test/config.json b/test/config.json
index 3f30a61..bcab5c0 100644
--- a/test/config.json
+++ b/test/config.json
@@ -4,6 +4,7 @@
       {"host" : "localhost", "port": 9201}
     ]
   },
+  "index_prefix": "graylog",
   "max_indices": 1,
   "backup_dir": "/srv/containers/elasticsearch_backups",
   "delete": false