diff --git a/.devcontainer/devcontainer.json b/.devcontainer/devcontainer.json
index b3fa6d4932..ab4f8cc960 100644
--- a/.devcontainer/devcontainer.json
+++ b/.devcontainer/devcontainer.json
@@ -40,6 +40,7 @@
         "yaml.customTags": [
           "!secret scalar",
           "!lambda scalar",
+          "!extend scalar",
           "!include_dir_named scalar",
           "!include_dir_list scalar",
           "!include_dir_merge_list scalar",