diff --git a/tests/inference_service_utils/http_inference_service_setup.py b/tests/inference_service_utils/http_inference_service_setup.py
index df3e7a38..3263d4d4 100644
--- a/tests/inference_service_utils/http_inference_service_setup.py
+++ b/tests/inference_service_utils/http_inference_service_setup.py
@@ -63,7 +63,7 @@ async def inference(inp: Request):
       grouped = result_df.groupby(name_to_input_cols[service_name])
       res_df_list = []
       for _, group in grouped:
-        group = group.drop(columns=name_to_input_cols[service_name]).dropna()
+        group = group.drop(columns=name_to_input_cols[service_name]).dropna(how='all')
         res_df_list.append(group.to_dict(orient='list'))
 
       return res_df_list