diff --git a/codex-cli/src/utils/agent/agent-loop.ts b/codex-cli/src/utils/agent/agent-loop.ts
index 97fc4edc..9882a49e 100644
--- a/codex-cli/src/utils/agent/agent-loop.ts
+++ b/codex-cli/src/utils/agent/agent-loop.ts
@@ -486,7 +486,7 @@ export class AgentLoop {
             let reasoning: Reasoning | undefined;
             if (this.model.startsWith("o")) {
               reasoning = { effort: "high" };
-              if (this.model === "o3-mini" || this.model === "o4-mini") {
+              if (this.model === "o3" || this.model === "o4-mini") {
                 // @ts-expect-error waiting for API type update
                 reasoning.summary = "auto";
               }
diff --git a/codex-cli/tests/agent-project-doc.test.ts b/codex-cli/tests/agent-project-doc.test.ts
index 17cc6cda..97ad9c8c 100644
--- a/codex-cli/tests/agent-project-doc.test.ts
+++ b/codex-cli/tests/agent-project-doc.test.ts
@@ -112,7 +112,7 @@ describe("AgentLoop", () => {
     expect(config.instructions).toContain("Hello docs!");
 
     const agent = new AgentLoop({
-      model: "o3-mini", // arbitrary
+      model: "o3", // arbitrary
       instructions: config.instructions,
       config,
       approvalPolicy: { mode: "suggest" } as any,