diff --git a/scripts/review_pr.py b/scripts/review_pr.py
index 77cdd0c..fca864a 100644
--- a/scripts/review_pr.py
+++ b/scripts/review_pr.py
@@ -18,6 +18,7 @@ import re
 import shutil
 import subprocess
 import sys
+import threading
 import urllib.error
 import urllib.request
 
@@ -335,21 +336,28 @@ def run_claude(claude_bin, project_root, prompt, extra_dir=None):
         text=True,
         encoding="utf-8",
     )
-    stdout_lines = []
-    for line in proc.stdout:
-        line = line.rstrip("\n")
-        stdout_lines.append(line)
-        if line:
-            print(f"[claude] {line}", file=sys.stderr)
 
+    def _stream(pipe, label, dest_lines):
+        for line in pipe:
+            line = line.rstrip("\n")
+            if line:
+                print(f"[{label}] {line}", file=sys.stderr)
+            dest_lines.append(line)
+
+    stderr_lines = []
+    t = threading.Thread(target=_stream, args=(proc.stderr, "claude:stderr", stderr_lines))
+    t.start()
+
+    stdout_lines = []
+    _stream(proc.stdout, "claude", stdout_lines)
+
+    t.join(timeout=10)
     proc.wait(timeout=600)
-    # Drain remaining stderr
-    stderr_output = proc.stderr.read()
-    if stderr_output:
-        print(stderr_output, file=sys.stderr)
 
     if proc.returncode != 0:
         print(f"Claude exited with code {proc.returncode}", file=sys.stderr)
+        if stderr_lines:
+            print("\n".join(stderr_lines[-50:]), file=sys.stderr)
         sys.exit(1)
     return "\n".join(stdout_lines)