diff --git a/docs/development/extensions-contrib/distinctcount.md b/docs/development/extensions-contrib/distinctcount.md
index f6c06143e4d..c9ef54581a9 100644
--- a/docs/development/extensions-contrib/distinctcount.md
+++ b/docs/development/extensions-contrib/distinctcount.md
@@ -83,7 +83,7 @@ Example:
 {
   "queryType": "groupBy",
   "dataSource": "sample_datasource",
-  "dimensions": "[sample_dim]",
+  "dimensions": ["sample_dim"],
   "granularity": "all",
   "aggregations": [
     {