diff --git a/src/backend/InvenTree/stock/api.py b/src/backend/InvenTree/stock/api.py
index 00119d1486..4e552ad445 100644
--- a/src/backend/InvenTree/stock/api.py
+++ b/src/backend/InvenTree/stock/api.py
@@ -1320,8 +1320,7 @@ class TestStatistics(GenericAPIView):
     )
     def get(self, request, pk, *args, **kwargs):
         """Return test execution count matrix broken down by test result."""
-        instance = self.get_object()
-        serializer = self.get_serializer(instance)
+        serializer = self.get_serializer(request.data)
         if request.resolver_match.url_name == 'api-test-statistics-by-part':
             serializer.context['type'] = 'by-part'
         elif request.resolver_match.url_name == 'api-test-statistics-by-build':
diff --git a/src/backend/InvenTree/stock/serializers.py b/src/backend/InvenTree/stock/serializers.py
index e92c133eb7..6f05d477c4 100644
--- a/src/backend/InvenTree/stock/serializers.py
+++ b/src/backend/InvenTree/stock/serializers.py
@@ -885,13 +885,15 @@ class TestStatisticsSerializer(serializers.Serializer):
     def to_representation(self, obj):
         """Just pass through the test statistics from the model."""
         if self.context['type'] == 'by-part':
-            return obj.part_test_statistics(
+            return StockItemTestResult.part_test_statistics(
+                {},
                 self.context['pk'],
                 self.context['finished_datetime_after'],
                 self.context['finished_datetime_before'],
             )
         elif self.context['type'] == 'by-build':
-            return obj.build_test_statistics(
+            return StockItemTestResult.build_test_statistics(
+                {},
                 self.context['pk'],
                 self.context['finished_datetime_after'],
                 self.context['finished_datetime_before'],