diff --git a/changelog.d/maintenance/8484-thinking-signature-recovery-types.md b/changelog.d/maintenance/8484-thinking-signature-recovery-types.md
new file mode 100644
index 0000000000..94c32a5b6e
--- /dev/null
+++ b/changelog.d/maintenance/8484-thinking-signature-recovery-types.md
@@ -0,0 +1 @@
+- **fix(types):** preserved the known first-failure record while reading Anthropic thinking-signature recovery details so TypeScript 7 keeps the retry result union narrow ([#8484](https://github.com/diegosouzapw/OmniRoute/issues/8484))
diff --git a/open-sse/handlers/chatCore/thinkingSignatureRecovery.ts b/open-sse/handlers/chatCore/thinkingSignatureRecovery.ts
index b0f080bd77..ab4fb1d931 100644
--- a/open-sse/handlers/chatCore/thinkingSignatureRecovery.ts
+++ b/open-sse/handlers/chatCore/thinkingSignatureRecovery.ts
@@ -69,7 +69,9 @@ export async function recoverAnthropicThinkingSignature(args: {
       return args.execute(requestBody);
     },
     getError: async (result) => {
-      if (result === firstFailure) return { status: result.status, message: result.message };
+      if (result === firstFailure) {
+        return { status: firstFailure.status, message: firstFailure.message };
+      }
       if (result.response.ok) return null;
       const details = await args.parseError(result.response.clone());
       return { status: details.statusCode, message: details.message };