diff --git a/src/gsp.py b/src/gsp.py
index aa0bf70..28c7bce 100644
--- a/src/gsp.py
+++ b/src/gsp.py
@@ -8,7 +8,7 @@
 from fastapi import APIRouter, Depends, Request, Security, status
 from fastapi.responses import Response
 from fastapi_auth0 import Auth0User
-from nowcasting_datamodel.fake import make_fake_forecast, make_fake_forecasts
+from nowcasting_datamodel.fake import make_fake_forecast, make_fake_forecasts, make_fake_gsp_yields
 from nowcasting_datamodel.models import Forecast, ForecastValue, ManyForecasts
 from sqlalchemy.orm.session import Session
 
@@ -277,9 +277,9 @@ def get_truths_for_all_gsps(
 
     if is_fake:
         if gsp_ids is None:
-            gsp_ids = [int(gsp_id) for gsp_id in range(1, GSP_TOTAL)]
+            gsp_ids = [List[int(gsp_id)] for gsp_id in range(1, GSP_TOTAL)]
 
-        make_fake_forecasts(gsp_ids=gsp_ids, session=session)
+        make_fake_gsp_yields(gsp_ids=gsp_ids, session=session)
 
     logger.info(f"Get PV Live estimates values for all gsp id and regime {regime} for user {user}")
 
@@ -315,7 +315,7 @@ def get_truths_for_a_specific_gsp_old_route(
     """Redirects old API route to new route /v0/solar/GB/gsp/{gsp_id}/pvlive"""
 
     if is_fake:
-        make_fake_forecast(gsp_id=gsp_id, session=session)
+        make_fake_gsp_yields(gsp_ids=List[gsp_id], session=session)
 
     return get_truths_for_a_specific_gsp(
         request=request,
diff --git a/src/national.py b/src/national.py
index 76a4d38..4331f77 100644
--- a/src/national.py
+++ b/src/national.py
@@ -10,7 +10,7 @@
 from elexonpy.api_client import ApiClient
 from fastapi import APIRouter, Depends, HTTPException, Query, Request, Security
 from fastapi_auth0 import Auth0User
-from nowcasting_datamodel.fake import make_fake_forecast
+from nowcasting_datamodel.fake import make_fake_forecast, make_fake_gsp_yields
 from nowcasting_datamodel.read.read import get_latest_forecast_for_gsps
 from sqlalchemy.orm.session import Session
 
@@ -215,7 +215,7 @@ def get_national_pvlive(
     logger.info(f"Get national PV Live estimates values " f"for regime {regime} for  {user}")
 
     if is_fake:
-        make_fake_forecast(gsp_id=gsp_id, session=session)
+        make_fake_gsp_yields(gsp_ids=List[gsp_id], session=session)
 
     return get_truth_values_for_a_specific_gsp_from_database(
         session=session, gsp_id=gsp_id, regime=regime