diff --git a/app.py b/app.py
index 718f881..a5706ec 100644
--- a/app.py
+++ b/app.py
@@ -109,6 +109,9 @@ def extract(username: str, password: str):
         historial_html_io = StringIO(f"<table>{historial_html}</table>")
         # Read the HTML table into a DataFrame
         df = pd.read_html(historial_html_io)[0]
+        
+        if 'GRUPO' not in df.columns:
+           raise KeyError("Column 'GRUPO' not found in the DataFrame")
 
         # Convert the DataFrame to JSON
         json_result = df[df['GRUPO'] != 'Promedio:'].to_json(orient='records')