diff --git a/doc/static/languages.json b/doc/static/languages.json
index 5769c1b335b..b1f1e541be5 100644
--- a/doc/static/languages.json
+++ b/doc/static/languages.json
@@ -3,6 +3,7 @@
         "name": "English",
         "versions": [
             "latest",
+            "9.1.x",
             "9.0.x",
             "8.1.x",
             "7.1.x"
@@ -12,6 +13,7 @@
         "name": "日本語",
         "versions": [
             "latest",
+            "9.1.x",
             "9.0.x",
             "8.1.x",
             "7.1.x"