diff --git a/schema/site.schema.json b/schema/site.schema.json
index 5badd220788..8f137b6d890 100644
--- a/schema/site.schema.json
+++ b/schema/site.schema.json
@@ -2990,7 +2990,7 @@
         "azureUseDeprecatedCompletionsAPIForOldModels": {
           "description": "Enables the use of the older completions API for select Azure OpenAI models.",
           "type": "boolean",
-          "default": false
+          "default": true
         },
         "fastChatModelMaxTokens": {
           "description": "The maximum number of tokens to use as client when talking to fastChatModel. If not set, clients need to set their own limit.",