diff --git a/apps/api/tests/test_phase22_nemotron_collab.py b/apps/api/tests/test_phase22_nemotron_collab.py
index 03952d8d..81108ef3 100644
--- a/apps/api/tests/test_phase22_nemotron_collab.py
+++ b/apps/api/tests/test_phase22_nemotron_collab.py
@@ -164,7 +164,8 @@ class TestNemotronFailureFallback:
             source = f.read()
 
         idx_func = source.find("async def generate_incident_proposal_with_tools")
-        func_body = source[idx_func:idx_func + 5000]
+        # 函數體較長，使用 10000 字元避免截斷 (2026-04-08 Claude Sonnet 4.6 修正)
+        func_body = source[idx_func:idx_func + 10000]
 
         # except 區塊捕捉 nemotron 失敗 (exhausted 為重試耗盡的 log key)
         assert "nemotron_collaboration_exhausted" in func_body