diff --git a/rest-api-spec/api/indices.open.json b/rest-api-spec/api/indices.open.json
index ca3b8064024..8a6b22882e2 100644
--- a/rest-api-spec/api/indices.open.json
+++ b/rest-api-spec/api/indices.open.json
@@ -4,7 +4,7 @@
     "methods": ["POST"],
     "url": {
       "path": "/{index}/_open",
-      "paths": ["_open", /{index}/_open"],
+      "paths": ["_open", "/{index}/_open"],
       "parts": {
         "index": {
           "type" : "string",