diff --git a/app/main.py b/app/main.py
index 3e0ce13..54275e2 100644
--- a/app/main.py
+++ b/app/main.py
@@ -3,6 +3,7 @@ from fastapi.middleware.cors import CORSMiddleware
 from fastapi.responses import JSONResponse
 from sqlmodel.ext.asyncio.session import AsyncSession
 from sqlmodel import select, func, text
+from sqlalchemy.exc import IntegrityError
 from .database import init_db, get_session, get_engine
 from .models import ErrorLog, ErrorLogCreate, LogStatus, TaskStatusUpdate, RepairTask, RepairTaskCreate, Project, ProjectUpdate
 from .gitea_client import GiteaClient
@@ -163,9 +164,29 @@ async def report_log(log_data: ErrorLogCreate, session: AsyncSession = Depends(g
     )
 
     session.add(new_log)
-    await session.commit()
-    await session.refresh(new_log)
+    try:
+        await session.commit()
+    except IntegrityError:
+        await session.rollback()
+        # Race condition: another request inserted the same fingerprint concurrently.
+        # Re-query and update the existing record instead.
+        dup_stmt = select(ErrorLog).where(ErrorLog.fingerprint == fingerprint)
+        dup_results = await session.exec(dup_stmt)
+        dup_log = dup_results.first()
+        if dup_log:
+            dup_log.error_message = log_data.error.get("message", dup_log.error_message)
+            dup_log.stack_trace = log_data.error.get("stack_trace", dup_log.stack_trace)
+            dup_log.context = log_data.context or dup_log.context
+            dup_log.timestamp = log_data.timestamp or datetime.utcnow()
+            if log_data.commit_hash:
+                dup_log.commit_hash = log_data.commit_hash
+            session.add(dup_log)
+            await session.commit()
+            await session.refresh(dup_log)
+            return {"message": "Log deduplicated (content updated)", "id": dup_log.id, "status": dup_log.status}
+        raise
 
+    await session.refresh(new_log)
     return {"message": "Log reported", "id": new_log.id}
 
 # ==================== Agent Tasks ====================
diff --git a/test_bug71.db b/test_bug71.db
new file mode 100644
index 0000000..1a25295
Binary files /dev/null and b/test_bug71.db differ