diff --git a/packages/adapters/codex-local/src/server/codex-args.test.ts b/packages/adapters/codex-local/src/server/codex-args.test.ts
index 9e9c614a56..931dea19ba 100644
--- a/packages/adapters/codex-local/src/server/codex-args.test.ts
+++ b/packages/adapters/codex-local/src/server/codex-args.test.ts
@@ -156,4 +156,45 @@ describe("buildCodexExecArgs", () => {
       "-",
     ]);
   });
+
+  it("does not add a second --skip-git-repo-check when extraArgs already carry it", () => {
+    const result = buildCodexExecArgs(
+      {
+        model: "gpt-5.5",
+        extraArgs: ["--skip-git-repo-check"],
+      },
+      { skipGitRepoCheck: true },
+    );
+
+    expect(result.args.filter((arg) => arg === "--skip-git-repo-check")).toHaveLength(1);
+    expect(result.args).toEqual([
+      "exec",
+      "--json",
+      "--model",
+      "gpt-5.5",
+      "--skip-git-repo-check",
+      "-",
+    ]);
+  });
+
+  it("does not add a second --skip-git-repo-check when the legacy args field carries it", () => {
+    const result = buildCodexExecArgs(
+      {
+        model: "gpt-5.5",
+        args: ["--skip-git-repo-check"],
+      },
+      { skipGitRepoCheck: true },
+    );
+
+    expect(result.args.filter((arg) => arg === "--skip-git-repo-check")).toHaveLength(1);
+  });
+
+  it("keeps the operator's --skip-git-repo-check when the sandbox injection is not requested", () => {
+    const result = buildCodexExecArgs({
+      model: "gpt-5.5",
+      extraArgs: ["--skip-git-repo-check"],
+    });
+
+    expect(result.args.filter((arg) => arg === "--skip-git-repo-check")).toHaveLength(1);
+  });
 });
diff --git a/packages/adapters/codex-local/src/server/codex-args.ts b/packages/adapters/codex-local/src/server/codex-args.ts
index 475345514f..db9b349c0a 100644
--- a/packages/adapters/codex-local/src/server/codex-args.ts
+++ b/packages/adapters/codex-local/src/server/codex-args.ts
@@ -5,6 +5,8 @@ import {
   normalizeCodexModel,
 } from "../index.js";
 
+const SKIP_GIT_REPO_CHECK_FLAG = "--skip-git-repo-check";
+
 export type BuildCodexExecArgsResult = {
   args: string[];
   model: string;
@@ -52,7 +54,14 @@ export function buildCodexExecArgs(
   const extraArgs = readExtraArgs(record);
 
   const args = ["exec", "--json"];
-  if (options.skipGitRepoCheck) args.push("--skip-git-repo-check");
+  // Codex rejects a repeated `--skip-git-repo-check` ("cannot be used multiple
+  // times"). The adapter injects this flag for sandbox execution, so when an
+  // operator's extraArgs already carry it the injection would abort the run
+  // with exit code 2. Skip the injection in that case and let the operator's
+  // copy stand.
+  if (options.skipGitRepoCheck && !extraArgs.includes(SKIP_GIT_REPO_CHECK_FLAG)) {
+    args.push(SKIP_GIT_REPO_CHECK_FLAG);
+  }
   if (search) args.unshift("--search");
   if (bypass) args.push("--dangerously-bypass-approvals-and-sandbox");
   if (model) args.push("--model", model);