diff --git a/app/services/ai_backend/open_ai.rb b/app/services/ai_backend/open_ai.rb
index 206d9ce4..39d2c57e 100644
--- a/app/services/ai_backend/open_ai.rb
+++ b/app/services/ai_backend/open_ai.rb
@@ -66,7 +66,7 @@ def set_client_config(config)
         model: @assistant.language_model.api_name,
         messages: system_message(config[:instructions]) + config[:messages],
         stream: config[:streaming] && @response_handler || nil,
-        max_tokens: 2000, # we should really set this dynamically, based on the model, to the max
+        max_completion_tokens: 2000, # we should really set this dynamically, based on the model, to the max
         stream_options: config[:streaming] && { include_usage: true } || nil,
         response_format: { type: "text" },
         tools: @assistant.language_model.supports_tools? && Toolbox.tools || nil,