diff --git a/src/acp/client-helpers.ts b/src/acp/client-helpers.ts
index 68da8b1aead0..891274293a22 100644
--- a/src/acp/client-helpers.ts
+++ b/src/acp/client-helpers.ts
@@ -123,13 +123,12 @@ export async function resolvePermissionRequest(
   const promptRequired = !classification.autoApprove;
 
   if (!promptRequired) {
-    const option = allowOption ?? options[0];
-    if (!option) {
-      log(`[permission cancelled] ${toolName}: no selectable options`);
+    if (!allowOption) {
+      log(`[permission cancelled] ${toolName ?? "unknown"}: missing allow option`);
       return cancelledPermission();
     }
     log(`[permission auto-approved] ${toolName} (${toolKind ?? "unknown"})`);
-    return selectedPermission(option.optionId);
+    return selectedPermission(allowOption.optionId);
   }
 
   log(
diff --git a/src/acp/client.test.ts b/src/acp/client.test.ts
index 3e54b6822b9e..2ff5d18b0cb0 100644
--- a/src/acp/client.test.ts
+++ b/src/acp/client.test.ts
@@ -659,6 +659,27 @@ describe("resolvePermissionRequest", () => {
     expect(res).toEqual({ outcome: { outcome: "selected", optionId: "reject-always" } });
   });
 
+  it("cancels auto-approved requests when no allow option is available", async () => {
+    const prompt = vi.fn(async () => true);
+    const log = vi.fn();
+    const res = await resolvePermissionRequest(
+      makePermissionRequest({
+        toolCall: {
+          toolCallId: "tool-read-no-allow",
+          title: "read: src/index.ts",
+          status: "pending",
+          kind: "read",
+        },
+        options: [{ kind: "reject_once", name: "Reject", optionId: "reject" }],
+      }),
+      { prompt, log },
+    );
+
+    expect(prompt).not.toHaveBeenCalled();
+    expect(log).toHaveBeenCalledWith("[permission cancelled] read: missing allow option");
+    expect(res).toEqual({ outcome: { outcome: "cancelled" } });
+  });
+
   it("prompts when tool identity is unknown and can still approve", async () => {
     const prompt = vi.fn(async () => true);
     const res = await resolvePermissionRequest(