diff --git a/app.py b/app.py
index 2d7234e..b8ab6d3 100644
--- a/app.py
+++ b/app.py
@@ -157,7 +157,7 @@ def extract(driver, username: str, password: str):
         historial_html_io = StringIO(f"<table>{historial_html}</table>")
         df = pd.read_html(historial_html_io)[0]
         
-        json_result = []
+        json_result = None
         
         if 'GRUPO' in df.columns:
             df['PERIODO'] = df['PERIODO'].apply(lambda x: str(x).replace('.0', '') if isinstance(x, (float, int)) else x)