diff --git a/backend/app/api/endpoints/base/historical_data.py b/backend/app/api/endpoints/base/historical_data.py
index deb65dea5..e3b72c4e9 100644
--- a/backend/app/api/endpoints/base/historical_data.py
+++ b/backend/app/api/endpoints/base/historical_data.py
@@ -3,6 +3,7 @@
 # LICENSE file in the root directory of this source tree.
 
 from fastapi import APIRouter
+from fastapi.exceptions import HTTPException
 
 from app.domain.schemas.base.historical_data import (
     GetDeleteHistoricalDataRequest,
@@ -24,9 +25,15 @@ async def get_historical_data_by_task_and_user(model: GetHistoricalDataRequest):
 
 @router.post("/save_historical_data")
 async def save_historical_data(model: GetSaveHistoricalDataRequest):
-    return HistoricalDataService().save_historical_data(
+    history = HistoricalDataService().save_historical_data(
         model.task_id, model.user_id, model.data
     )
+    if history:
+        return history
+    else:
+        raise HTTPException(
+            status_code=400, detail="Historical data already exists for this task"
+        )
 
 
 @router.post("/delete_historical_data")
diff --git a/backend/app/domain/services/base/historical_data.py b/backend/app/domain/services/base/historical_data.py
index b0e676950..b172ed923 100644
--- a/backend/app/domain/services/base/historical_data.py
+++ b/backend/app/domain/services/base/historical_data.py
@@ -15,9 +15,12 @@ def get_historical_data_by_task_and_user(self, task_id: int, user_id: int):
         )
 
     def save_historical_data(self, task_id: int, user_id: int, data: str):
-        return self.historical_data_repository.save_historical_data(
+        if not self.historical_data_repository.check_if_historical_data_exists(
             task_id, user_id, data
-        )
+        ):
+            return self.historical_data_repository.save_historical_data(
+                task_id, user_id, data
+            )
 
     def delete_historical_data(self, task_id: int, user_id: int):
         self.historical_data_repository.delete_historical_data(task_id, user_id)
diff --git a/backend/app/infrastructure/repositories/historical_data.py b/backend/app/infrastructure/repositories/historical_data.py
index 15d4e48e5..6590d9bd5 100644
--- a/backend/app/infrastructure/repositories/historical_data.py
+++ b/backend/app/infrastructure/repositories/historical_data.py
@@ -35,3 +35,12 @@ def delete_historical_data(self, task_id: int, user_id: int):
         ).filter(HistoricalData.user_id == user_id).delete()
         self.session.flush()
         self.session.commit()
+
+    def check_if_historical_data_exists(self, task_id: int, user_id: int, data: str):
+        return (
+            self.session.query(HistoricalData)
+            .filter(HistoricalData.task_id == task_id)
+            .filter(HistoricalData.user_id == user_id)
+            .filter(HistoricalData.history == data)
+            .first()
+        )