diff --git a/src/acp-agent.ts b/src/acp-agent.ts
index d3c72d33..7ad9554c 100644
--- a/src/acp-agent.ts
+++ b/src/acp-agent.ts
@@ -5042,7 +5042,9 @@ export class ClaudeAcpAgent {
                   const goalCommandFailed =
                     message.is_error ||
                     message.stop_reason === "refusal" ||
-                    ("result" in message && message.result.includes("Please run /login"));
+                    ("result" in message &&
+                      message.is_error &&
+                      message.result.includes("Please run /login"));
                   if (goalCommandFailed) {
                     await this.publishGoal(params.sessionId, pendingGoalUpdate.previous ?? null);
                   }
@@ -5406,7 +5408,7 @@ export class ClaudeAcpAgent {
 
               switch (message.subtype) {
                 case "success": {
-                  if (message.result.includes("Please run /login")) {
+                  if (message.is_error && message.result.includes("Please run /login")) {
                     await failActiveWithSessionFailure(
                       "auth_required",
                       RequestError.authRequired(),
diff --git a/src/tests/acp-agent.test.ts b/src/tests/acp-agent.test.ts
index a0d48239..cae687b0 100644
--- a/src/tests/acp-agent.test.ts
+++ b/src/tests/acp-agent.test.ts
@@ -7439,6 +7439,35 @@ describe("stop reason propagation", () => {
     expect(logged.join("\n")).not.toContain("cannot fail active turn");
   });
 
+  it("does not treat a successful answer mentioning /login as auth_required", async () => {
+    const updates: SessionNotification[] = [];
+    const agent = new ClaudeAcpAgent(
+      {
+        sessionUpdate: async (update: SessionNotification) => {
+          updates.push(update);
+        },
+      } as unknown as AcpClient,
+      { log: () => {}, error: () => {} },
+    );
+    (agent as any).clientCapabilities = airSessionFailureCapabilities;
+    const answer = "A normal answer can quote: Please run /login.";
+    injectSession(agent, [
+      createAssistantError(undefined, answer),
+      createResultMessage({
+        subtype: "success",
+        stop_reason: "end_turn",
+        is_error: false,
+        result: answer,
+      }),
+      { type: "system", subtype: "session_state_changed", state: "idle" },
+    ]);
+
+    await expect(
+      agent.prompt({ sessionId: "test-session", prompt: [{ type: "text", text: "test" }] }),
+    ).resolves.toMatchObject({ stopReason: "end_turn" });
+    expect(sessionFailuresFromUpdates(updates)).toEqual([]);
+  });
+
   it("republishes the signed-out state after a real model answer cleared the last one", async () => {
     const updates: SessionNotification[] = [];
     const agent = new ClaudeAcpAgent(