diff --git a/src/cron/isolated-agent/run.ts b/src/cron/isolated-agent/run.ts
index 3f6e06f4b7..422a81fe32 100644
--- a/src/cron/isolated-agent/run.ts
+++ b/src/cron/isolated-agent/run.ts
@@ -232,7 +232,10 @@ export async function runCronIsolatedAgentTurn(params: {
     });
   }
   if (thinkLevel === "xhigh" && !supportsXHighThinking(provider, model)) {
-    throw new Error(`Thinking level "xhigh" is only supported for ${formatXHighModelHint()}.`);
+    logWarn(
+      `[cron:${params.job.id}] Thinking level "xhigh" is not supported for ${provider}/${model}; downgrading to "high".`,
+    );
+    thinkLevel = "high";
   }
 
   const timeoutMs = resolveAgentTimeoutMs({