diff --git a/crates/language_models/src/provider/copilot_chat.rs b/crates/language_models/src/provider/copilot_chat.rs
index a77e3f880be18d8f9f0e97ec8717c32bc780e267..8b46c38f2524a048d60ba4b2892b200a824f69e8 100644
--- a/crates/language_models/src/provider/copilot_chat.rs
+++ b/crates/language_models/src/provider/copilot_chat.rs
@@ -405,7 +405,10 @@ impl LanguageModel for CopilotChatLanguageModel {
                 if model.supports_adaptive_thinking() {
                     if anthropic_request.thinking.is_some() {
                         anthropic_request.thinking = Some(anthropic::Thinking::Adaptive);
-                        anthropic_request.output_config = Some(anthropic::OutputConfig { effort });
+                        anthropic_request.output_config =
+                            effort.map(|effort| anthropic::OutputConfig {
+                                effort: Some(effort),
+                            });
                     }
                 }