diff --git a/packages/opencode/src/session/prompt.ts b/packages/opencode/src/session/prompt.ts
index 392413a4..c6140325 100644
--- a/packages/opencode/src/session/prompt.ts
+++ b/packages/opencode/src/session/prompt.ts
@@ -1548,7 +1548,7 @@ export namespace SessionPrompt {
       ...ProviderTransform.options(small.providerID, small.modelID, input.session.id),
       ...small.info.options,
     }
-    if (small.providerID === "openai") {
+    if (small.providerID === "openai" || small.modelID.includes("gpt-5")) {
       options["reasoningEffort"] = "minimal"
     }
     if (small.providerID === "google") {