diff --git a/src/definitions/behaviors/api.js b/src/definitions/behaviors/api.js
index ee7e610dd8..8cab14f564 100644
--- a/src/definitions/behaviors/api.js
+++ b/src/definitions/behaviors/api.js
@@ -1208,7 +1208,7 @@ $.api.settings = {
   regExp  : {
     required : /\{\$*[A-z0-9]+\}/g,
     optional : /\{\/\$*[A-z0-9]+\}/g,
-    validate: /^[a-z_][a-z0-9_-]*(?:\[(?:\d*|[a-z0-9_-]+)\])*$/i,
+    validate: /^[a-z_][a-z0-9_-]*(?:\[[a-z0-9_-]*\])*$/i,
     key:      /[a-z0-9_-]+|(?=\[\])/gi,
     push:     /^$/,
     fixed:    /^\d+$/,